/* http://keith-wood.name/datepick.html
   Date picker for jQuery v4.1.0.
   Written by Keith Wood (kbwood{at}iinet.com.au) February 2010.
   Dual licensed under the GPL (http://dev.jquery.com/browser/trunk/jquery/GPL-LICENSE.txt) and 
   MIT (http://dev.jquery.com/browser/trunk/jquery/MIT-LICENSE.txt) licenses. 
   Please attribute the author if you use it. */

   (function($) { // Hide scope, no $ conflict

    /* Datepicker manager. */
    function Datepicker() {
        this._defaults = {
            pickerClass: '', // CSS class to add to this instance of the datepicker
            showOnFocus: true, // True for popup on focus, false for not
            showTrigger: null, // Element to be cloned for a trigger, null for none
            showAnim: 'show', // Name of jQuery animation for popup, '' for no animation
            showOptions: {}, // Options for enhanced animations
            showSpeed: 'normal', // Duration of display/closure
            popupContainer: null, // The element to which a popup calendar is added, null for body
            alignment: 'bottom', // Alignment of popup - with nominated corner of input:
                // 'top' or 'bottom' aligns depending on language direction,
                // 'topLeft', 'topRight', 'bottomLeft', 'bottomRight'
            fixedWeeks: false, // True to always show 6 weeks, false to only show as many as are needed
            firstDay: 0, // First day of the week, 0 = Sunday, 1 = Monday, ...
            calculateWeek: this.iso8601Week, // Calculate week of the year from a date, null for ISO8601
            monthsToShow: 1, // How many months to show, cols or [rows, cols]
            monthsOffset: 0, // How many months to offset the primary month by;
                // may be a function that takes the date and returns the offset
            monthsToStep: 1, // How many months to move when prev/next clicked
            monthsToJump: 12, // How many months to move when large prev/next clicked
            useMouseWheel: true, // True to use mousewheel if available, false to never use it
            changeMonth: true, // True to change month/year via drop-down, false for navigation only
            yearRange: 'c-100:c+1', // Range of years to show in drop-down: 'any' for direct text entry
                // or 'start:end', where start/end are '+-nn' for relative to today
                // or 'c+-nn' for relative to the currently selected date
                // or 'nnnn' for an absolute year
            //shortYearCutoff: '+1',
            shortYearCutoff: '+1',// Cutoff for two-digit year in the current century
            showOtherMonths: false, // True to show dates from other months, false to not show them
            selectOtherMonths: false, // True to allow selection of dates from other months too
            defaultDate: null, // Date to show if no other selected
            selectDefaultDate: false, // True to pre-select the default date if no other is chosen
            minDate: null, // The minimum selectable date
            maxDate: null, // The maximum selectable date
            dateFormat: 'dd-mm-yyyy', // Format for dates
            autoSize: false, // True to size the input field according to the date format
            rangeSelect: false, // Allows for selecting a date range on one date picker
            rangeSeparator: ' - ', // Text between two dates in a range
            multiSelect: 0, // Maximum number of selectable dates, zero for single select
            multiSeparator: ',', // Text between multiple dates
            onDate: null, // Callback as a date is added to the datepicker
            onShow: null, // Callback just before a datepicker is shown
            onChangeMonthYear: null, // Callback when a new month/year is selected
            onSelect: null, // Callback when a date is selected
            onClose: null, // Callback when a datepicker is closed
            altField: null, // Alternate field to update in synch with the datepicker
            altFormat: null, // Date format for alternate field, defaults to dateFormat
            constrainInput: true, // True to constrain typed input to dateFormat allowed characters
            commandsAsDateFormat: false, // True to apply formatDate to the command texts
            commands: this.commands // Command actions that may be added to a layout by name
        };
        this.regional = [];
        this.regional[''] = { // US/English
            monthNames: ['January', 'February', 'March', 'April', 'May', 'June',
            'July', 'August', 'September', 'October', 'November', 'December'],
            monthNamesShort: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
            dayNames: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'],
            dayNamesShort: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'],
            dayNamesMin: ['Su', 'Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa'],
            dateFormat: 'dd-mm-yyyy', // See options on formatDate
            firstDay: 0, // The first day of the week, Sun = 0, Mon = 1, ...
            renderer: this.defaultRenderer, // The rendering templates
            prevText: '&lt;Prev', // Text for the previous month command
            prevStatus: 'Show the previous month', // Status text for the previous month command
            prevJumpText: '&lt;&lt;', // Text for the previous year command
            prevJumpStatus: 'Show the previous year', // Status text for the previous year command
            nextText: 'Next&gt;', // Text for the next month command
            nextStatus: 'Show the next month', // Status text for the next month command
            nextJumpText: '&gt;&gt;', // Text for the next year command
            nextJumpStatus: 'Show the next year', // Status text for the next year command
            currentText: 'Current', // Text for the current month command
            currentStatus: 'Show the current month', // Status text for the current month command
            todayText: 'Today', // Text for the today's month command
            todayStatus: 'Show today\'s month', // Status text for the today's month command
            clearText: 'Clear', // Text for the clear command
            clearStatus: 'Clear all the dates', // Status text for the clear command
            closeText: 'Close', // Text for the close command
            closeStatus: 'Close the datepicker', // Status text for the close command
            yearStatus: 'Change the year', // Status text for year selection
            monthStatus: 'Change the month', // Status text for month selection
            weekText: 'Wk', // Text for week of the year column header
            weekStatus: 'Week of the year', // Status text for week of the year column header
            dayStatus: 'Select DD, M d, yyyy', // Status text for selectable days
            defaultStatus: 'Select a date', // Status text shown by default
            isRTL: false // True if language is right-to-left
        };
        $.extend(this._defaults, this.regional['']);
        this._disabled = [];
    }
    
    $.extend(Datepicker.prototype, {
        /* Class name added to elements to indicate already configured with datepicker. */
        markerClassName: 'hasDatepick',
        /* Name of the data property for instance settings. */
        propertyName: 'datepick',
    
        _popupClass: 'datepick-popup', // Marker for popup division
        _triggerClass: 'datepick-trigger', // Marker for trigger element
        _disableClass: 'datepick-disable', // Marker for disabled element
        _monthYearClass: 'datepick-month-year', // Marker for month/year inputs
        _curMonthClass: 'datepick-month-', // Marker for current month/year
        _anyYearClass: 'datepick-any-year', // Marker for year direct input
        _curDoWClass: 'datepick-dow-', // Marker for day of week
        
        commands: { // Command actions that may be added to a layout by name
            // name: { // The command name, use '{button:name}' or '{link:name}' in layouts
            //		text: '', // The field in the regional settings for the displayed text
            //		status: '', // The field in the regional settings for the status text
            //      // The keystroke to trigger the action
            //		keystroke: {keyCode: nn, ctrlKey: boolean, altKey: boolean, shiftKey: boolean},
            //		enabled: fn, // The function that indicates the command is enabled
            //		date: fn, // The function to get the date associated with this action
            //		action: fn} // The function that implements the action
            prev: {text: 'prevText', status: 'prevStatus', // Previous month
                keystroke: {keyCode: 33}, // Page up
                enabled: function(inst) {
                    var minDate = inst.curMinDate();
                    return (!minDate || plugin.add(plugin.day(
                        plugin._applyMonthsOffset(plugin.add(plugin.newDate(inst.drawDate),
                        1 - inst.options.monthsToStep, 'm'), inst), 1), -1, 'd').
                        getTime() >= minDate.getTime()); },
                date: function(inst) {
                    return plugin.day(plugin._applyMonthsOffset(plugin.add(
                        plugin.newDate(inst.drawDate), -inst.options.monthsToStep, 'm'), inst), 1); },
                action: function(inst) {
                    plugin._changeMonthPlugin(this, -inst.options.monthsToStep); }
            },
            prevJump: {text: 'prevJumpText', status: 'prevJumpStatus', // Previous year
                keystroke: {keyCode: 33, ctrlKey: true}, // Ctrl + Page up
                enabled: function(inst) {
                    var minDate = inst.curMinDate();
                    return (!minDate || plugin.add(plugin.day(
                        plugin._applyMonthsOffset(plugin.add(plugin.newDate(inst.drawDate),
                        1 - inst.options.monthsToJump, 'm'), inst), 1), -1, 'd').
                        getTime() >= minDate.getTime()); },
                date: function(inst) {
                    return plugin.day(plugin._applyMonthsOffset(plugin.add(
                        plugin.newDate(inst.drawDate), -inst.options.monthsToJump, 'm'), inst), 1); },
                action: function(inst) {
                    plugin._changeMonthPlugin(this, -inst.options.monthsToJump); }
            },
            next: {text: 'nextText', status: 'nextStatus', // Next month
                keystroke: {keyCode: 34}, // Page down
                enabled: function(inst) {
                    var maxDate = inst.get('maxDate');
                    return (!maxDate || plugin.day(plugin._applyMonthsOffset(plugin.add(
                        plugin.newDate(inst.drawDate), inst.options.monthsToStep, 'm'), inst), 1).
                        getTime() <= maxDate.getTime()); },
                date: function(inst) {
                    return plugin.day(plugin._applyMonthsOffset(plugin.add(
                        plugin.newDate(inst.drawDate), inst.options.monthsToStep, 'm'), inst), 1); },
                action: function(inst) {
                    plugin._changeMonthPlugin(this, inst.options.monthsToStep); }
            },
            nextJump: {text: 'nextJumpText', status: 'nextJumpStatus', // Next year
                keystroke: {keyCode: 34, ctrlKey: true}, // Ctrl + Page down
                enabled: function(inst) {
                    var maxDate = inst.get('maxDate');
                    return (!maxDate || plugin.day(plugin._applyMonthsOffset(plugin.add(
                        plugin.newDate(inst.drawDate), inst.options.monthsToJump, 'm'), inst), 1).
                        getTime() <= maxDate.getTime()); },
                date: function(inst) {
                    return plugin.day(plugin._applyMonthsOffset(plugin.add(
                        plugin.newDate(inst.drawDate), inst.options.monthsToJump, 'm'), inst), 1); },
                action: function(inst) {
                    plugin._changeMonthPlugin(this, inst.options.monthsToJump); }
            },
            current: {text: 'currentText', status: 'currentStatus', // Current month
                keystroke: {keyCode: 36, ctrlKey: true}, // Ctrl + Home
                enabled: function(inst) {
                    var minDate = inst.curMinDate();
                    var maxDate = inst.get('maxDate');
                    var curDate = inst.selectedDates[0] || plugin.today();
                    return (!minDate || curDate.getTime() >= minDate.getTime()) &&
                        (!maxDate || curDate.getTime() <= maxDate.getTime()); },
                date: function(inst) {
                    return inst.selectedDates[0] || plugin.today(); },
                action: function(inst) {
                    var curDate = inst.selectedDates[0] || plugin.today();
                    plugin._showMonthPlugin(this, curDate.getFullYear(), curDate.getMonth() + 1); }
            },
            today: {text: 'todayText', status: 'todayStatus', // Today's month
                keystroke: {keyCode: 36, ctrlKey: true}, // Ctrl + Home
                enabled: function(inst) {
                    var minDate = inst.curMinDate();
                    var maxDate = inst.get('maxDate');
                    return (!minDate || plugin.today().getTime() >= minDate.getTime()) &&
                        (!maxDate || plugin.today().getTime() <= maxDate.getTime()); },
                date: function(inst) { return plugin.today(); },
                action: function(inst) { plugin._showMonthPlugin(this); }
            },
            clear: {text: 'clearText', status: 'clearStatus', // Clear the datepicker
                keystroke: {keyCode: 35, ctrlKey: true}, // Ctrl + End
                enabled: function(inst) { return true; },
                date: function(inst) { return null; },
                action: function(inst) { plugin._clearPlugin(this); }
            },
            close: {text: 'closeText', status: 'closeStatus', // Close the datepicker
                keystroke: {keyCode: 27}, // Escape
                enabled: function(inst) { return true; },
                date: function(inst) { return null; },
                action: function(inst) { plugin._hidePlugin(this); }
            },
            prevWeek: {text: 'prevWeekText', status: 'prevWeekStatus', // Previous week
                keystroke: {keyCode: 38, ctrlKey: true}, // Ctrl + Up
                enabled: function(inst) {
                    var minDate = inst.curMinDate();
                    return (!minDate || plugin.add(plugin.newDate(inst.drawDate), -7, 'd').
                        getTime() >= minDate.getTime()); },
                date: function(inst) { return plugin.add(plugin.newDate(inst.drawDate), -7, 'd'); },
                action: function(inst) { plugin._changeDayPlugin(this, -7); }
            },
            prevDay: {text: 'prevDayText', status: 'prevDayStatus', // Previous day
                keystroke: {keyCode: 37, ctrlKey: true}, // Ctrl + Left
                enabled: function(inst) {
                    var minDate = inst.curMinDate();
                    return (!minDate || plugin.add(plugin.newDate(inst.drawDate), -1, 'd').
                        getTime() >= minDate.getTime()); },
                date: function(inst) { return plugin.add(plugin.newDate(inst.drawDate), -1, 'd'); },
                action: function(inst) { plugin._changeDayPlugin(this, -1); }
            },
            nextDay: {text: 'nextDayText', status: 'nextDayStatus', // Next day
                keystroke: {keyCode: 39, ctrlKey: true}, // Ctrl + Right
                enabled: function(inst) {
                    var maxDate = inst.get('maxDate');
                    return (!maxDate || plugin.add(plugin.newDate(inst.drawDate), 1, 'd').
                        getTime() <= maxDate.getTime()); },
                date: function(inst) { return plugin.add(plugin.newDate(inst.drawDate), 1, 'd'); },
                action: function(inst) { plugin._changeDayPlugin(this, 1); }
            },
            nextWeek: {text: 'nextWeekText', status: 'nextWeekStatus', // Next week
                keystroke: {keyCode: 40, ctrlKey: true}, // Ctrl + Down
                enabled: function(inst) {
                    var maxDate = inst.get('maxDate');
                    return (!maxDate || plugin.add(plugin.newDate(inst.drawDate), 7, 'd').
                        getTime() <= maxDate.getTime()); },
                date: function(inst) { return plugin.add(plugin.newDate(inst.drawDate), 7, 'd'); },
                action: function(inst) { plugin._changeDayPlugin(this, 7); }
            }
        },
    
        /* Default template for generating a datepicker. */
        defaultRenderer: {
            // Anywhere: '{l10n:name}' to insert localised value for name,
            // '{link:name}' to insert a link trigger for command name,
            // '{button:name}' to insert a button trigger for command name,
            // '{popup:start}...{popup:end}' to mark a section for inclusion in a popup datepicker only,
            // '{inline:start}...{inline:end}' to mark a section for inclusion in an inline datepicker only
            // Overall structure: '{months}' to insert calendar months
            picker: '<div class="datepick">' +
            '<div class="datepick-nav">{link:prev}{link:today}{link:next}</div>{months}' +
            '{popup:start}<div class="datepick-ctrl">{link:clear}{link:close}</div>{popup:end}' +
            '<div class="datepick-clear-fix"></div></div>',
            // One row of months: '{months}' to insert calendar months
            monthRow: '<div class="datepick-month-row">{months}</div>',
            // A single month: '{monthHeader:dateFormat}' to insert the month header -
            // dateFormat is optional and defaults to 'MM yyyy',
            // '{weekHeader}' to insert a week header, '{weeks}' to insert the month's weeks
            month: '<div class="datepick-month"><div class="datepick-month-header">{monthHeader}</div>' +
            '<table><thead>{weekHeader}</thead><tbody>{weeks}</tbody></table></div>',
            // A week header: '{days}' to insert individual day names
            weekHeader: '<tr>{days}</tr>',
            // Individual day header: '{day}' to insert day name
            dayHeader: '<th>{day}</th>',
            // One week of the month: '{days}' to insert the week's days, '{weekOfYear}' to insert week of year
            week: '<tr>{days}</tr>',
            // An individual day: '{day}' to insert day value
            day: '<td>{day}</td>',
            // jQuery selector, relative to picker, for a single month
            monthSelector: '.datepick-month',
            // jQuery selector, relative to picker, for individual days
            daySelector: 'td',
            // Class for right-to-left (RTL) languages
            rtlClass: 'datepick-rtl',
            // Class for multi-month datepickers
            multiClass: 'datepick-multi',
            // Class for selectable dates
            defaultClass: '',
            // Class for currently selected dates
            selectedClass: 'datepick-selected',
            // Class for highlighted dates
            highlightedClass: 'datepick-highlight',
            // Class for today
            todayClass: 'datepick-today',
            // Class for days from other months
            otherMonthClass: 'datepick-other-month',
            // Class for days on weekends
            weekendClass: 'datepick-weekend',
            // Class prefix for commands
            commandClass: 'datepick-cmd',
            // Extra class(es) for commands that are buttons
            commandButtonClass: '',
            // Extra class(es) for commands that are links
            commandLinkClass: '',
            // Class for disabled commands
            disabledClass: 'datepick-disabled'
        },
    
        /* Override the default settings for all datepicker instances.
           @param  options  (object) the new settings to use as defaults
           @return  (Datepicker) this object */
        setDefaults: function(options) {
            $.extend(this._defaults, options || {});
            return this;
        },
    
        _ticksTo1970: (((1970 - 1) * 365 + Math.floor(1970 / 4) - Math.floor(1970 / 100) +
            Math.floor(1970 / 400)) * 24 * 60 * 60 * 10000000),
        _msPerDay: 24 * 60 * 60 * 1000,
    
        ATOM: 'yyyy-mm-dd', // RFC 3339/ISO 8601
        COOKIE: 'D, dd M yyyy',
        FULL: 'DD, MM d, yyyy',
        ISO_8601: 'yyyy-mm-dd',
        JULIAN: 'J',
        RFC_822: 'D, d M yy',
        RFC_850: 'DD, dd-M-yy',
        RFC_1036: 'D, d M yy',
        RFC_1123: 'D, d M yyyy',
        RFC_2822: 'D, d M yyyy',
        RSS: 'D, d M yy', // RFC 822
        TICKS: '!',
        TIMESTAMP: '@',
        W3C: 'yyyy-mm-dd', // ISO 8601
    
        /* Format a date object into a string value.
           The format can be combinations of the following:
           d  - day of month (no leading zero)
           dd - day of month (two digit)
           o  - day of year (no leading zeros)
           oo - day of year (three digit)
           D  - day name short
           DD - day name long
           w  - week of year (no leading zero)
           ww - week of year (two digit)
           m  - month of year (no leading zero)
           mm - month of year (two digit)
           M  - month name short
           MM - month name long
           yy - year (two digit)
           yyyy - year (four digit)
           @  - Unix timestamp (s since 01/01/1970)
           !  - Windows ticks (100ns since 01/01/0001)
           '...' - literal text
           '' - single quote
           @param  format    (string) the desired format of the date (optional, default datepicker format)
           @param  date      (Date) the date value to format
           @param  settings  (object) attributes include:
                             dayNamesShort    (string[]) abbreviated names of the days from Sunday (optional)
                             dayNames         (string[]) names of the days from Sunday (optional)
                             monthNamesShort  (string[]) abbreviated names of the months (optional)
                             monthNames       (string[]) names of the months (optional)
                             calculateWeek    (function) function that determines week of the year (optional)
           @return  (string) the date in the above format */
        formatDate: function(format, date, settings) {
            if (typeof format != 'string') {
                settings = date;
                date = format;
                format = '';
            }
            if (!date) {
                return '';
            }
            format = format || this._defaults.dateFormat;
            settings = settings || {};
            var dayNamesShort = settings.dayNamesShort || this._defaults.dayNamesShort;
            var dayNames = settings.dayNames || this._defaults.dayNames;
            var monthNamesShort = settings.monthNamesShort || this._defaults.monthNamesShort;
            var monthNames = settings.monthNames || this._defaults.monthNames;
            var calculateWeek = settings.calculateWeek || this._defaults.calculateWeek;
            // Check whether a format character is doubled
            var doubled = function(match, step) {
                var matches = 1;
                while (iFormat + matches < format.length && format.charAt(iFormat + matches) == match) {
                    matches++;
                }
                iFormat += matches - 1;
                return Math.floor(matches / (step || 1)) > 1;
            };
            // Format a number, with leading zeroes if necessary
            var formatNumber = function(match, value, len, step) {
                var num = '' + value;
                if (doubled(match, step)) {
                    while (num.length < len) {
                        num = '0' + num;
                    }
                }
                return num;
            };
            // Format a name, short or long as requested
            var formatName = function(match, value, shortNames, longNames) {
                return (doubled(match) ? longNames[value] : shortNames[value]);
            };
            var output = '';
            var literal = false;
            for (var iFormat = 0; iFormat < format.length; iFormat++) {
                if (literal) {
                    if (format.charAt(iFormat) == "'" && !doubled("'")) {
                        literal = false;
                    }
                    else {
                        output += format.charAt(iFormat);
                    }
                }
                else {
                    switch (format.charAt(iFormat)) {
                        case 'd': output += formatNumber('d', date.getDate(), 2); break;
                        case 'D': output += formatName('D', date.getDay(),
                            dayNamesShort, dayNames); break;
                        case 'o': output += formatNumber('o', this.dayOfYear(date), 3); break;
                        case 'w': output += formatNumber('w', calculateWeek(date), 2); break;
                        case 'm': output += formatNumber('m', date.getMonth() + 1, 2); break;
                        case 'M': output += formatName('M', date.getMonth(),
                            monthNamesShort, monthNames); break;
                        case 'y':
                            output += (doubled('y', 2) ? date.getFullYear() :
                                (date.getFullYear() % 100 < 10 ? '0' : '') + date.getFullYear() % 100);
                            break;
                        case '@': output += Math.floor(date.getTime() / 1000); break;
                        case '!': output += date.getTime() * 10000 + this._ticksTo1970; break;
                        case "'":
                            if (doubled("'")) {
                                output += "'";
                            }
                            else {
                                literal = true;
                            }
                            break;
                        default:
                            output += format.charAt(iFormat);
                    }
                }
            }
            return output;
        },
    
        /* Parse a string value into a date object.
           See formatDate for the possible formats, plus:
           * - ignore rest of string
           @param  format    (string) the expected format of the date ('' for default datepicker format)
           @param  value     (string) the date in the above format
           @param  settings  (object) attributes include:
                             shortYearCutoff  (number) the cutoff year for determining the century (optional)
                             dayNamesShort    (string[]) abbreviated names of the days from Sunday (optional)
                             dayNames         (string[]) names of the days from Sunday (optional)
                             monthNamesShort  (string[]) abbreviated names of the months (optional)
                             monthNames       (string[]) names of the months (optional)
           @return  (Date) the extracted date value or null if value is blank
           @throws  errors if the format and/or value are missing,
                    if the value doesn't match the format,
                    or if the date is invalid */
        parseDate: function(format, value, settings) {
            if (value == null) {
                throw 'Invalid arguments';
            }
            value = (typeof value == 'object' ? value.toString() : value + '');
            if (value == '') {
                return null;
            }
            format = format || this._defaults.dateFormat;
            settings = settings || {};
            var shortYearCutoff = settings.shortYearCutoff || this._defaults.shortYearCutoff;
            shortYearCutoff = (typeof shortYearCutoff != 'string' ? shortYearCutoff :
                this.today().getFullYear() % 100 + parseInt(shortYearCutoff, 10));
            var dayNamesShort = settings.dayNamesShort || this._defaults.dayNamesShort;
            var dayNames = settings.dayNames || this._defaults.dayNames;
            var monthNamesShort = settings.monthNamesShort || this._defaults.monthNamesShort;
            var monthNames = settings.monthNames || this._defaults.monthNames;
            var year = -1;
            var month = -1;
            var day = -1;
            var doy = -1;
            var shortYear = false;
            var literal = false;
            // Check whether a format character is doubled
            var doubled = function(match, step) {
                var matches = 1;
                while (iFormat + matches < format.length && format.charAt(iFormat + matches) == match) {
                    matches++;
                }
                iFormat += matches - 1;
                return Math.floor(matches / (step || 1)) > 1;
            };
            // Extract a number from the string value
            var getNumber = function(match, step) {
                var isDoubled = doubled(match, step);
                var size = [2, 3, isDoubled ? 4 : 2, 11, 20]['oy@!'.indexOf(match) + 1];
                var digits = new RegExp('^-?\\d{1,' + size + '}');
                var num = value.substring(iValue).match(digits);
                if (!num) {
                    throw 'Missing number at position {0}'.replace(/\{0\}/, iValue);
                }
                iValue += num[0].length;
                return parseInt(num[0], 10);
            };
            // Extract a name from the string value and convert to an index
            var getName = function(match, shortNames, longNames, step) {
                var names = (doubled(match, step) ? longNames : shortNames);
                for (var i = 0; i < names.length; i++) {
                    if (value.substr(iValue, names[i].length).toLowerCase() == names[i].toLowerCase()) {
                        iValue += names[i].length;
                        return i + 1;
                    }
                }
                throw 'Unknown name at position {0}'.replace(/\{0\}/, iValue);
            };
            // Confirm that a literal character matches the string value
            var checkLiteral = function() {
                if (value.charAt(iValue) != format.charAt(iFormat)) {
                    throw 'Unexpected literal at position {0}'.replace(/\{0\}/, iValue);
                }
                iValue++;
            };
            var iValue = 0;
            for (var iFormat = 0; iFormat < format.length; iFormat++) {
                if (literal) {
                    if (format.charAt(iFormat) == "'" && !doubled("'")) {
                        literal = false;
                    }
                    else {
                        checkLiteral();
                    }
                }
                else {
                    switch (format.charAt(iFormat)) {
                        case 'd': day = getNumber('d'); break;
                        case 'D': getName('D', dayNamesShort, dayNames); break;
                        case 'o': doy = getNumber('o'); break;
                        case 'w': getNumber('w'); break;
                        case 'm': month = getNumber('m'); break;
                        case 'M': month = getName('M', monthNamesShort, monthNames); break;
                        case 'y':
                            var iSave = iFormat;
                            shortYear = !doubled('y', 2);
                            iFormat = iSave;
                            year = getNumber('y', 2);
                            break;
                        case '@':
                            var date = this._normaliseDate(new Date(getNumber('@') * 1000));
                            year = date.getFullYear();
                            month = date.getMonth() + 1;
                            day = date.getDate();
                            break;
                        case '!':
                            var date = this._normaliseDate(
                                new Date((getNumber('!') - this._ticksTo1970) / 10000));
                            year = date.getFullYear();
                            month = date.getMonth() + 1;
                            day = date.getDate();
                            break;
                        case '*': iValue = value.length; break;
                        case "'":
                            if (doubled("'")) {
                                checkLiteral();
                            }
                            else {
                                literal = true;
                            }
                            break;
                        default: checkLiteral();
                    }
                }
            }
            if (iValue < value.length) {
                throw 'Additional text found at end';
            }
            if (year == -1) {
                year = this.today().getFullYear();
            }
            else if (year < 100 && shortYear) {
                year += (shortYearCutoff == -1 ? 1900 : this.today().getFullYear() -
                    this.today().getFullYear() % 100 - (year <= shortYearCutoff ? 0 : 100));
            }
            if (doy > -1) {
                month = 1;
                day = doy;
                for (var dim = this.daysInMonth(year, month); day > dim;
                        dim = this.daysInMonth(year, month)) {
                    month++;
                    day -= dim;
                }
            }
            var date = this.newDate(year, month, day);
            if (date.getFullYear() != year || date.getMonth() + 1 != month || date.getDate() != day) {
                throw 'Invalid date';
            }
            return date;
        },
    
        /* A date may be specified as an exact value or a relative one.
           @param  dateSpec     (Date or number or string) the date as an object or string
                                in the given format or an offset - numeric days from today,
                                or string amounts and periods, e.g. '+1m +2w'
           @param  defaultDate  (Date) the date to use if no other supplied, may be null
           @param  currentDate  (Date) the current date as a possible basis for relative dates,
                                if null today is used (optional)
           @param  dateFormat   (string) the expected date format - see formatDate above (optional)
           @param  settings     (object) attributes include:
                                shortYearCutoff  (number) the cutoff year for determining the century (optional)
                                dayNamesShort    (string[7]) abbreviated names of the days from Sunday (optional)
                                dayNames         (string[7]) names of the days from Sunday (optional)
                                monthNamesShort  (string[12]) abbreviated names of the months (optional)
                                monthNames       (string[12]) names of the months (optional)
           @return  (Date) the decoded date */
        determineDate: function(dateSpec, defaultDate, currentDate, dateFormat, settings) {
            if (currentDate && typeof currentDate != 'object') {
                settings = dateFormat;
                dateFormat = currentDate;
                currentDate = null;
            }
            if (typeof dateFormat != 'string') {
                settings = dateFormat;
                dateFormat = '';
            }
            var offsetString = function(offset) {
                try {
                    return plugin.parseDate(dateFormat, offset, settings);
                }
                catch (e) {
                    // Ignore
                }
                offset = offset.toLowerCase();
                var date = (offset.match(/^c/) && currentDate ? plugin.newDate(currentDate) : null) ||
                    plugin.today();
                var pattern = /([+-]?[0-9]+)\s*(d|w|m|y)?/g;
                var matches = null;
                while (matches = pattern.exec(offset)) {
                    date = plugin.add(date, parseInt(matches[1], 10), matches[2] || 'd');
                }
                return date;
            };
            defaultDate = (defaultDate ? plugin.newDate(defaultDate) : null);
            dateSpec = (dateSpec == null ? defaultDate :
                (typeof dateSpec == 'string' ? offsetString(dateSpec) : (typeof dateSpec == 'number' ?
                (isNaN(dateSpec) || dateSpec == Infinity || dateSpec == -Infinity ? defaultDate :
                plugin.add(plugin.today(), dateSpec, 'd')) : plugin.newDate(dateSpec))));
            return dateSpec;
        },
    
        /* Find the number of days in a given month.
           @param  year   (Date) the date to get days for or
                          (number) the full year
           @param  month  (number) the month (1 to 12)
           @return  (number) the number of days in this month */
        daysInMonth: function(year, month) {
            month = (year.getFullYear ? year.getMonth() + 1 : month);
            year = (year.getFullYear ? year.getFullYear() : year);
            return this.newDate(year, month + 1, 0).getDate();
        },
    
        /* Calculate the day of the year for a date.
           @param  year   (Date) the date to get the day-of-year for or
                          (number) the full year
           @param  month  (number) the month (1-12)
           @param  day    (number) the day
           @return  (number) the day of the year */
        dayOfYear: function(year, month, day) {
            var date = (year.getFullYear ? year : this.newDate(year, month, day));
            var newYear = this.newDate(date.getFullYear(), 1, 1);
            return Math.floor((date.getTime() - newYear.getTime()) / this._msPerDay) + 1;
        },
    
        /* Set as calculateWeek to determine the week of the year based on the ISO 8601 definition.
           @param  year   (Date) the date to get the week for or
                          (number) the full year
           @param  month  (number) the month (1-12)
           @param  day    (number) the day
           @return  (number) the number of the week within the year that contains this date */
        iso8601Week: function(year, month, day) {
            var checkDate = (year.getFullYear ?
                new Date(year.getTime()) : this.newDate(year, month, day));
            // Find Thursday of this week starting on Monday
            checkDate.setDate(checkDate.getDate() + 4 - (checkDate.getDay() || 7));
            var time = checkDate.getTime();
            checkDate.setMonth(0, 1); // Compare with Jan 1
            return Math.floor(Math.round((time - checkDate) / 86400000) / 7) + 1;
        },
    
        /* Return today's date.
           @return  (Date) today */
        today: function() {
            return this._normaliseDate(new Date());
        },
    
        /* Return a new date.
           @param  year   (Date) the date to clone or
                          (number) the year
           @param  month  (number) the month (1-12)
           @param  day    (number) the day
           @return  (Date) the date */
        newDate: function(year, month, day) {
            return (!year ? null : (year.getFullYear ? this._normaliseDate(new Date(year.getTime())) :
                new Date(year, month - 1, day, 12)));
        },
    
        /* Standardise a date into a common format - time portion is 12 noon.
           @param  date  (Date) the date to standardise
           @return  (Date) the normalised date */
        _normaliseDate: function(date) {
            if (date) {
                date.setHours(12, 0, 0, 0);
            }
            return date;
        },
    
        /* Set the year for a date.
           @param  date  (Date) the original date
           @param  year  (number) the new year
           @return  the updated date */
        year: function(date, year) {
            date.setFullYear(year);
            return this._normaliseDate(date);
        },
    
        /* Set the month for a date.
           @param  date   (Date) the original date
           @param  month  (number) the new month (1-12)
           @return  the updated date */
        month: function(date, month) {
            date.setMonth(month - 1);
            return this._normaliseDate(date);
        },
    
        /* Set the day for a date.
           @param  date  (Date) the original date
           @param  day   (number) the new day of the month
           @return  the updated date */
        day: function(date, day) {
            date.setDate(day);
            return this._normaliseDate(date);
        },
    
        /* Add a number of periods to a date.
           @param  date    (Date) the original date
           @param  amount  (number) the number of periods
           @param  period  (string) the type of period d/w/m/y
           @return  the updated date */
        add: function(date, amount, period) {
            if (period == 'd' || period == 'w') {
                this._normaliseDate(date);
                date.setDate(date.getDate() + amount * (period == 'w' ? 7 : 1));
            }
            else {
                var year = date.getFullYear() + (period == 'y' ? amount : 0);
                var month = date.getMonth() + (period == 'm' ? amount : 0);
                date.setTime(plugin.newDate(year, month + 1,
                    Math.min(date.getDate(), this.daysInMonth(year, month + 1))).getTime());
            }
            return date;
        },
    
        /* Apply the months offset value to a date.
           @param  date  (Date) the original date
           @param  inst  (object) the current instance settings
           @return  (Date) the updated date */
        _applyMonthsOffset: function(date, inst) {
            var monthsOffset = inst.options.monthsOffset;
            if ($.isFunction(monthsOffset)) {
                monthsOffset = monthsOffset.apply(inst.target[0], [date]);
            }
            return plugin.add(date, -monthsOffset, 'm');
        },
    
        /* Attach the datepicker functionality to an input field.
           @param  target   (element) the control to affect
           @param  options  (object) the custom options for this instance */
        _attachPlugin: function(target, options) {
            target = $(target);
            if (target.hasClass(this.markerClassName)) {
                return;
            }
            var inlineSettings = ($.fn.metadata ? target.metadata() : {});
            var inst = {options: $.extend({}, this._defaults, inlineSettings, options),
                target: target, selectedDates: [], drawDate: null, pickingRange: false,
                inline: ($.inArray(target[0].nodeName.toLowerCase(), ['div', 'span']) > -1),
                get: function(name) { // Get a setting value, computing if necessary
                    if ($.inArray(name, ['defaultDate', 'minDate', 'maxDate']) > -1) { // Decode date settings
                        return plugin.determineDate(this.options[name], null,
                            this.selectedDates[0], this.options.dateFormat, inst.getConfig());
                    }
                    return this.options[name];
                },
                curMinDate: function() {
                    return (this.pickingRange ? this.selectedDates[0] : this.get('minDate'));
                },
                getConfig: function() {
                    return {dayNamesShort: this.options.dayNamesShort, dayNames: this.options.dayNames,
                        monthNamesShort: this.options.monthNamesShort, monthNames: this.options.monthNames,
                        calculateWeek: this.options.calculateWeek,
                        shortYearCutoff: this.options.shortYearCutoff};
                }
            };
            target.addClass(this.markerClassName).data(this.propertyName, inst);
            if (inst.inline) {
                inst.drawDate = plugin._checkMinMax(plugin.newDate(inst.selectedDates[0] ||
                    inst.get('defaultDate') || plugin.today()), inst);
                inst.prevDate = plugin.newDate(inst.drawDate);
                this._update(target[0]);
                if ($.fn.mousewheel) {
                    target.mousewheel(this._doMouseWheel);
                }
            }
            else {
                this._attachments(target, inst);
                target.bind('keydown.' + this.propertyName, this._keyDown).
                    bind('keypress.' + this.propertyName, this._keyPress).
                    bind('keyup.' + this.propertyName, this._keyUp);
                if (target.attr('disabled')) {
                    this._disablePlugin(target[0]);
                }
            }
        },
    
        /* Retrieve or reconfigure the settings for a control.
           @param  target   (element) the control to affect
           @param  options  (object) the new options for this instance or
                            (string) an individual property name
           @param  value    (any) the individual property value (omit if options
                            is an object or to retrieve the value of a setting)
           @return  (any) if retrieving a value */
        _optionPlugin: function(target, options, value) {
            target = $(target);
            var inst = target.data(this.propertyName);
            if (!options || (typeof options == 'string' && value == null)) { // Get option
                var name = options;
                options = (inst || {}).options;
                return (options && name ? options[name] : options);
            }
    
            if (!target.hasClass(this.markerClassName)) {
                return;
            }
            options = options || {};
            if (typeof options == 'string') {
                var name = options;
                options = {};
                options[name] = value;
            }
            if (options.calendar && options.calendar != inst.options.calendar) {
                var discardDate = function(name) {
                    return (typeof inst.options[name] == 'object' ? null : inst.options[name]);
                };
                options = $.extend({defaultDate: discardDate('defaultDate'),
                    minDate: discardDate('minDate'), maxDate: discardDate('maxDate')}, options);
                inst.selectedDates = [];
                inst.drawDate = null;
            }
            var dates = inst.selectedDates;
            $.extend(inst.options, options);
            this._setDatePlugin(target[0], dates, null, false, true);
            inst.pickingRange = false;
            inst.drawDate = plugin.newDate(this._checkMinMax(
                (inst.options.defaultDate ? inst.get('defaultDate') : inst.drawDate) ||
                inst.get('defaultDate') || plugin.today(), inst));
            if (!inst.inline) {
                this._attachments(target, inst);
            }
            if (inst.inline || inst.div) {
                this._update(target[0]);
            }
        },
    
        /* Attach events and trigger, if necessary.
           @param  target  (jQuery) the control to affect
           @param  inst    (object) the current instance settings */
        _attachments: function(target, inst) {
            target.unbind('focus.' + this.propertyName);
            if (inst.options.showOnFocus) {
                target.bind('focus.' + this.propertyName, this._showPlugin);
            }
            if (inst.trigger) {
                inst.trigger.remove();
            }
            var trigger = inst.options.showTrigger;
            inst.trigger = (!trigger ? $([]) :
                $(trigger).clone().removeAttr('id').addClass(this._triggerClass)
                    [inst.options.isRTL ? 'insertBefore' : 'insertAfter'](target).
                    click(function() {
                        if (!plugin._isDisabledPlugin(target[0])) {
                            plugin[plugin.curInst == inst ? '_hidePlugin' : '_showPlugin'](target[0]);
                        }
                    }));
            this._autoSize(target, inst);
            var dates = this._extractDates(inst, target.val());
            if (dates) {
                this._setDatePlugin(target[0], dates, null, true);
            }
            var defaultDate = inst.get('defaultDate');
            if (inst.options.selectDefaultDate && defaultDate && inst.selectedDates.length == 0) {
                this._setDatePlugin(target[0], plugin.newDate(defaultDate || plugin.today()));
            }
        },
    
        /* Apply the maximum length for the date format.
           @param  inst  (object) the current instance settings */
        _autoSize: function(target, inst) {
            if (inst.options.autoSize && !inst.inline) {
                var date = plugin.newDate(2009, 10, 20); // Ensure double digits
                var dateFormat = inst.options.dateFormat;
                if (dateFormat.match(/[DM]/)) {
                    var findMax = function(names) {
                        var max = 0;
                        var maxI = 0;
                        for (var i = 0; i < names.length; i++) {
                            if (names[i].length > max) {
                                max = names[i].length;
                                maxI = i;
                            }
                        }
                        return maxI;
                    };
                    date.setMonth(findMax(inst.options[dateFormat.match(/MM/) ? // Longest month
                        'monthNames' : 'monthNamesShort']));
                    date.setDate(findMax(inst.options[dateFormat.match(/DD/) ? // Longest day
                        'dayNames' : 'dayNamesShort']) + 20 - date.getDay());
                }
                inst.target.attr('size', plugin.formatDate(dateFormat, date, inst.getConfig()).length);
            }
        },
    
        /* Remove the datepicker functionality from a control.
           @param  target  (element) the control to affect */
        _destroyPlugin: function(target) {
            target = $(target);
            if (!target.hasClass(this.markerClassName)) {
                return;
            }
            var inst = target.data(this.propertyName);
            if (inst.trigger) {
                inst.trigger.remove();
            }
            target.removeClass(this.markerClassName).removeData(this.propertyName).
                empty().unbind('.' + this.propertyName);
            if (inst.inline && $.fn.mousewheel) {
                target.unmousewheel();
            }
            if (!inst.inline && inst.options.autoSize) {
                target.removeAttr('size');
            }
        },
    
        /* Apply multiple event functions.
           Usage, for example: onShow: multipleEvents(fn1, fn2, ...)
           @param  fns  (function...) the functions to apply */
        multipleEvents: function(fns) {
            var funcs = arguments;
            return function(args) {
                for (var i = 0; i < funcs.length; i++) {
                    funcs[i].apply(this, arguments);
                }
            };
        },
    
        /* Enable the control.
           @param  target  (element) the control to affect */
        _enablePlugin: function(target) {
            target = $(target);
            if (!target.hasClass(this.markerClassName)) {
                return;
            }
            var inst = target.data(this.propertyName);
            if (inst.inline) {
                target.children('.' + this._disableClass).remove().end().
                    find('button,select').removeAttr('disabled').end().
                    find('a').attr('href', 'javascript:void(0)');
            }
            else {
                target.prop('disabled', false);
                inst.trigger.filter('button.' + this._triggerClass).
                    removeAttr('disabled').end().
                    filter('img.' + this._triggerClass).
                    css({opacity: '1.0', cursor: ''});
            }
            this._disabled = $.map(this._disabled,
                function(value) { return (value == target[0] ? null : value); }); // Delete entry
        },
    
        /* Disable the control.
           @param  target  (element) the control to affect */
        _disablePlugin: function(target) {
            target = $(target);
            if (!target.hasClass(this.markerClassName)) {
                return;
            }
            var inst = target.data(this.propertyName);
            if (inst.inline) {
                var inline = target.children(':last');
                var offset = inline.offset();
                var relOffset = {left: 0, top: 0};
                inline.parents().each(function() {
                    if ($(this).css('position') == 'relative') {
                        relOffset = $(this).offset();
                        return false;
                    }
                });
                var zIndex = target.css('zIndex');
                zIndex = (zIndex == 'auto' ? 0 : parseInt(zIndex, 10)) + 1;
                target.prepend('<div class="' + this._disableClass + '" style="' +
                    'width: ' + inline.outerWidth() + 'px; height: ' + inline.outerHeight() +
                    'px; left: ' + (offset.left - relOffset.left) + 'px; top: ' +
                    (offset.top - relOffset.top) + 'px; z-index: ' + zIndex + '"></div>').
                    find('button,select').attr('disabled', 'disabled').end().
                    find('a').removeAttr('href');
            }
            else {
                target.prop('disabled', true);
                inst.trigger.filter('button.' + this._triggerClass).
                    attr('disabled', 'disabled').end().
                    filter('img.' + this._triggerClass).
                    css({opacity: '0.5', cursor: 'default'});
            }
            this._disabled = $.map(this._disabled,
                function(value) { return (value == target[0] ? null : value); }); // Delete entry
            this._disabled.push(target[0]);
        },
    
        /* Is the first field in a jQuery collection disabled as a datepicker?
           @param  target  (element) the control to examine
           @return  (boolean) true if disabled, false if enabled */
        _isDisabledPlugin: function(target) {
            return (target && $.inArray(target, this._disabled) > -1);
        },
    
        /* Show a popup datepicker.
           @param  target  (event) a focus event or
                           (element) the control to use */
        _showPlugin: function(target) {
            target = $(target.target || target);
            var inst = target.data(plugin.propertyName);
            if (plugin.curInst == inst) {
                return;
            }
            if (plugin.curInst) {
                plugin._hidePlugin(plugin.curInst, true);
            }
            if (inst) {
                // Retrieve existing date(s)
                inst.lastVal = null;
                inst.selectedDates = plugin._extractDates(inst, target.val());
                inst.pickingRange = false;
                inst.drawDate = plugin._checkMinMax(plugin.newDate(inst.selectedDates[0] ||
                    inst.get('defaultDate') || plugin.today()), inst);
                inst.prevDate = plugin.newDate(inst.drawDate);
                plugin.curInst = inst;
                // Generate content
                plugin._update(target[0], true);
                // Adjust position before showing
                var offset = plugin._checkOffset(inst);
                inst.div.css({left: offset.left, top: offset.top});
                // And display
                var showAnim = inst.options.showAnim;
                var showSpeed = inst.options.showSpeed;
                showSpeed = (showSpeed == 'normal' && $.ui && $.ui.version >= '1.8' ?
                    '_default' : showSpeed);
                if ($.effects && $.effects[showAnim]) {
                    var data = inst.div.data(); // Update old effects data
                    for (var key in data) {
                        if (key.match(/^ec\.storage\./)) {
                            data[key] = inst._mainDiv.css(key.replace(/ec\.storage\./, ''));
                        }
                    }
                    inst.div.data(data).show(showAnim, inst.options.showOptions, showSpeed);
                }
                else {
                    inst.div[showAnim || 'show']((showAnim ? showSpeed : ''));
                }
            }
        },
    
        /* Extract possible dates from a string.
           @param  inst  (object) the current instance settings
           @param  text  (string) the text to extract from
           @return  (CDate[]) the extracted dates */
        _extractDates: function(inst, datesText) {
            if (datesText == inst.lastVal) {
                return;
            }
            inst.lastVal = datesText;
            datesText = datesText.split(inst.options.multiSelect ? inst.options.multiSeparator :
                (inst.options.rangeSelect ? inst.options.rangeSeparator : '\x00'));
            var dates = [];
            for (var i = 0; i < datesText.length; i++) {
                try {
                    var date = plugin.parseDate(inst.options.dateFormat, datesText[i], inst.getConfig());
                    if (date) {
                        var found = false;
                        for (var j = 0; j < dates.length; j++) {
                            if (dates[j].getTime() == date.getTime()) {
                                found = true;
                                break;
                            }
                        }
                        if (!found) {
                            dates.push(date);
                        }
                    }
                }
                catch (e) {
                    // Ignore
                }
            }
            dates.splice(inst.options.multiSelect || (inst.options.rangeSelect ? 2 : 1), dates.length);
            if (inst.options.rangeSelect && dates.length == 1) {
                dates[1] = dates[0];
            }
            return dates;
        },
    
        /* Update the datepicker display.
           @param  target  (event) a focus event or
                           (element) the control to use
           @param  hidden  (boolean) true to initially hide the datepicker */
        _update: function(target, hidden) {
            target = $(target.target || target);
            var inst = target.data(plugin.propertyName);
            if (inst) {
                if (inst.inline || plugin.curInst == inst) {
                    if ($.isFunction(inst.options.onChangeMonthYear) && (!inst.prevDate ||
                            inst.prevDate.getFullYear() != inst.drawDate.getFullYear() ||
                            inst.prevDate.getMonth() != inst.drawDate.getMonth())) {
                        inst.options.onChangeMonthYear.apply(target[0],
                            [inst.drawDate.getFullYear(), inst.drawDate.getMonth() + 1]);
                    }
                }
                if (inst.inline) {
                    target.html(this._generateContent(target[0], inst));
                }
                else if (plugin.curInst == inst) {
                    if (!inst.div) {
                        inst.div = $('<div></div>').addClass(this._popupClass).
                            css({display: (hidden ? 'none' : 'static'), position: 'absolute',
                                left: target.offset().left,
                                top: target.offset().top + target.outerHeight()}).
                            appendTo($(inst.options.popupContainer || 'body'));
                        if ($.fn.mousewheel) {
                            inst.div.mousewheel(this._doMouseWheel);
                        }
                    }
                    inst.div.html(this._generateContent(target[0], inst));
                    target.focus();
                }
            }
        },
    
        /* Update the input field and any alternate field with the current dates.
           @param  target  (element) the control to use
           @param  keyUp   (boolean, internal) true if coming from keyUp processing */
        _updateInput: function(target, keyUp) {
            var inst = $.data(target, this.propertyName);
            if (inst) {
                var value = '';
                var altValue = '';
                var sep = (inst.options.multiSelect ? inst.options.multiSeparator :
                    inst.options.rangeSeparator);
                var altFormat = inst.options.altFormat || inst.options.dateFormat;
                for (var i = 0; i < inst.selectedDates.length; i++) {
                    value += (keyUp ? '' : (i > 0 ? sep : '') + plugin.formatDate(
                        inst.options.dateFormat, inst.selectedDates[i], inst.getConfig()));
                    altValue += (i > 0 ? sep : '') + plugin.formatDate(
                        altFormat, inst.selectedDates[i], inst.getConfig());
                }
                if (!inst.inline && !keyUp) {
                    $(target).val(value);
                }
                $(inst.options.altField).val(altValue);
                if ($.isFunction(inst.options.onSelect) && !keyUp && !inst.inSelect) {
                    inst.inSelect = true; // Prevent endless loops
                    inst.options.onSelect.apply(target, [inst.selectedDates]);
                    inst.inSelect = false;
                }
            }
        },
    
        /* Retrieve the size of left and top borders for an element.
           @param  elem  (jQuery) the element of interest
           @return  (number[2]) the left and top borders */
        _getBorders: function(elem) {
            var convert = function(value) {
                return {thin: 1, medium: 3, thick: 5}[value] || value;
            };
            return [parseFloat(convert(elem.css('border-left-width'))),
                parseFloat(convert(elem.css('border-top-width')))];
        },
    
        /* Check positioning to remain on the screen.
           @param  inst  (object) the current instance settings
           @return  (object) the updated offset for the datepicker */
        _checkOffset: function(inst) {
            var base = (inst.target.is(':hidden') && inst.trigger ? inst.trigger : inst.target);
            var offset = base.offset();
            var browserWidth = $(window).width();
            var browserHeight = $(window).height();
            if (browserWidth == 0) {
                return offset;
            }
            var isFixed = false;
            $(inst.target).parents().each(function() {
                isFixed |= $(this).css('position') == 'fixed';
                return !isFixed;
            });
            var scrollX = document.documentElement.scrollLeft || document.body.scrollLeft;
            var scrollY = document.documentElement.scrollTop || document.body.scrollTop;
            var above = offset.top - (isFixed ? scrollY : 0) - inst.div.outerHeight();
            var below = offset.top - (isFixed ? scrollY : 0) + base.outerHeight();
            var alignL = offset.left - (isFixed ? scrollX : 0);
            var alignR = offset.left - (isFixed ? scrollX : 0) + base.outerWidth() - inst.div.outerWidth();
            var tooWide = (offset.left - scrollX + inst.div.outerWidth()) > browserWidth;
            var tooHigh = (offset.top - scrollY + inst.target.outerHeight() +
                inst.div.outerHeight()) > browserHeight;
            inst.div.css('position', isFixed ? 'fixed' : 'absolute');
            var alignment = inst.options.alignment;
            if (alignment == 'topLeft') {
                offset = {left: alignL, top: above};
            }
            else if (alignment == 'topRight') {
                offset = {left: alignR, top: above};
            }
            else if (alignment == 'bottomLeft') {
                offset = {left: alignL, top: below};
            }
            else if (alignment == 'bottomRight') {
                offset = {left: alignR, top: below};
            }
            else if (alignment == 'top') {
                offset = {left: (inst.options.isRTL || tooWide ? alignR : alignL), top: above};
            }
            else { // bottom
                offset = {left: (inst.options.isRTL || tooWide ? alignR : alignL),
                    top: (tooHigh ? above : below)};
            }
            offset.left = Math.max((isFixed ? 0 : scrollX), offset.left);
            offset.top = Math.max((isFixed ? 0 : scrollY), offset.top);
            return offset;
        },
    
        /* Close date picker if clicked elsewhere.
           @param  event  (MouseEvent) the mouse click to check */
        _checkExternalClick: function(event) {
            if (!plugin.curInst) {
                return;
            }
            var target = $(event.target);
            if (!target.parents().andSelf().hasClass(plugin._popupClass) &&
                    !target.hasClass(plugin.markerClassName) &&
                    !target.parents().andSelf().hasClass(plugin._triggerClass)) {
                plugin._hidePlugin(plugin.curInst);
            }
        },
    
        /* Hide a popup datepicker.
           @param  target     (element) the control to use or
                              (object) the current instance settings
           @param  immediate  (boolean) true to close immediately without animation */
        _hidePlugin: function(target, immediate) {
            if (!target) {
                return;
            }
            var inst = $.data(target, this.propertyName) || target;
            if (inst && inst == plugin.curInst) {
                var showAnim = (immediate ? '' : inst.options.showAnim);
                var showSpeed = inst.options.showSpeed;
                showSpeed = (showSpeed == 'normal' && $.ui && $.ui.version >= '1.8' ?
                    '_default' : showSpeed);
                var postProcess = function() {
                    if (!inst.div) {
                        return;
                    }
                    inst.div.remove();
                    inst.div = null;
                    plugin.curInst = null;
                    if ($.isFunction(inst.options.onClose)) {
                        inst.options.onClose.apply(target, [inst.selectedDates]);
                    }
                };
                inst.div.stop();
                if ($.effects && $.effects[showAnim]) {
                    inst.div.hide(showAnim, inst.options.showOptions, showSpeed, postProcess);
                }
                else {
                    var hideAnim = (showAnim == 'slideDown' ? 'slideUp' :
                        (showAnim == 'fadeIn' ? 'fadeOut' : 'hide'));
                    inst.div[hideAnim]((showAnim ? showSpeed : ''), postProcess);
                }
                if (!showAnim) {
                    postProcess();
                }
            }
        },
    
        /* Handle keystrokes in the datepicker.
           @param  event  (KeyEvent) the keystroke
           @return  (boolean) true if not handled, false if handled */
        _keyDown: function(event) {
            var target = event.target;
            var inst = $.data(target, plugin.propertyName);
            var handled = false;
            if (inst.div) {
                if (event.keyCode == 9) { // Tab - close
                    plugin._hidePlugin(target);
                }
                else if (event.keyCode == 13) { // Enter - select
                    plugin._selectDatePlugin(target,
                        $('a.' + inst.options.renderer.highlightedClass, inst.div)[0]);
                    handled = true;
                }
                else { // Command keystrokes
                    var commands = inst.options.commands;
                    for (var name in commands) {
                        var command = commands[name];
                        if (command.keystroke.keyCode == event.keyCode &&
                                !!command.keystroke.ctrlKey == !!(event.ctrlKey || event.metaKey) &&
                                !!command.keystroke.altKey == event.altKey &&
                                !!command.keystroke.shiftKey == event.shiftKey) {
                            plugin._performActionPlugin(target, name);
                            handled = true;
                            break;
                        }
                    }
                }
            }
            else { // Show on 'current' keystroke
                var command = inst.options.commands.current;
                if (command.keystroke.keyCode == event.keyCode &&
                        !!command.keystroke.ctrlKey == !!(event.ctrlKey || event.metaKey) &&
                        !!command.keystroke.altKey == event.altKey &&
                        !!command.keystroke.shiftKey == event.shiftKey) {
                    plugin._showPlugin(target);
                    handled = true;
                }
            }
            inst.ctrlKey = ((event.keyCode < 48 && event.keyCode != 32) ||
                event.ctrlKey || event.metaKey);
            if (handled) {
                event.preventDefault();
                event.stopPropagation();
            }
            return !handled;
        },
    
        /* Filter keystrokes in the datepicker.
           @param  event  (KeyEvent) the keystroke
           @return  (boolean) true if allowed, false if not allowed */
        _keyPress: function(event) {
            var inst = $.data(event.target, plugin.propertyName);
            if (inst && inst.options.constrainInput) {
                var ch = String.fromCharCode(event.keyCode || event.charCode);
                var allowedChars = plugin._allowedChars(inst);
                return (event.metaKey || inst.ctrlKey || ch < ' ' ||
                    !allowedChars || allowedChars.indexOf(ch) > -1);
            }
            return true;
        },
    
        /* Determine the set of characters allowed by the date format.
           @param  inst  (object) the current instance settings
           @return  (string) the set of allowed characters, or null if anything allowed */
        _allowedChars: function(inst) {
            var allowedChars = (inst.options.multiSelect ? inst.options.multiSeparator :
                (inst.options.rangeSelect ? inst.options.rangeSeparator : ''));
            var literal = false;
            var hasNum = false;
            var dateFormat = inst.options.dateFormat;
            for (var i = 0; i < dateFormat.length; i++) {
                var ch = dateFormat.charAt(i);
                if (literal) {
                    if (ch == "'" && dateFormat.charAt(i + 1) != "'") {
                        literal = false;
                    }
                    else {
                        allowedChars += ch;
                    }
                }
                else {
                    switch (ch) {
                        case 'd': case 'm': case 'o': case 'w':
                            allowedChars += (hasNum ? '' : '0123456789'); hasNum = true; break;
                        case 'y': case '@': case '!':
                            allowedChars += (hasNum ? '' : '0123456789') + '-'; hasNum = true; break;
                        case 'J':
                            allowedChars += (hasNum ? '' : '0123456789') + '-.'; hasNum = true; break;
                        case 'D': case 'M': case 'Y':
                            return null; // Accept anything
                        case "'":
                            if (dateFormat.charAt(i + 1) == "'") {
                                allowedChars += "'";
                            }
                            else {
                                literal = true;
                            }
                            break;
                        default:
                            allowedChars += ch;
                    }
                }
            }
            return allowedChars;
        },
    
        /* Synchronise datepicker with the field.
           @param  event  (KeyEvent) the keystroke
           @return  (boolean) true if allowed, false if not allowed */
        _keyUp: function(event) {
            var target = event.target;
            var inst = $.data(target, plugin.propertyName);
            if (inst && !inst.ctrlKey && inst.lastVal != inst.target.val()) {
                try {
                    var dates = plugin._extractDates(inst, inst.target.val());
                    if (dates.length > 0) {
                        plugin._setDatePlugin(target, dates, null, true);
                    }
                }
                catch (event) {
                    // Ignore
                }
            }
            return true;
        },
    
        /* Increment/decrement month/year on mouse wheel activity.
           @param  event  (event) the mouse wheel event
           @param  delta  (number) the amount of change */
        _doMouseWheel: function(event, delta) {
            var target = (plugin.curInst && plugin.curInst.target[0]) ||
                $(event.target).closest('.' + plugin.markerClassName)[0];
            if (plugin._isDisabledPlugin(target)) {
                return;
            }
            var inst = $.data(target, plugin.propertyName);
            if (inst.options.useMouseWheel) {
                delta = (delta < 0 ? -1 : +1);
                plugin._changeMonthPlugin(target,
                    -inst.options[event.ctrlKey ? 'monthsToJump' : 'monthsToStep'] * delta);
            }
            event.preventDefault();
        },
    
        /* Clear an input and close a popup datepicker.
           @param  target  (element) the control to use */
        _clearPlugin: function(target) {
            var inst = $.data(target, this.propertyName);
            if (inst) {
                inst.selectedDates = [];
                this._hidePlugin(target);
                var defaultDate = inst.get('defaultDate');
                if (inst.options.selectDefaultDate && defaultDate) {
                    this._setDatePlugin(target, plugin.newDate(defaultDate || plugin.today()));
                }
                else {
                    this._updateInput(target);
                }
            }
        },
    
        /* Retrieve the selected date(s) for a datepicker.
           @param  target  (element) the control to examine
           @return  (CDate[]) the selected date(s) */
        _getDatePlugin: function(target) {
            var inst = $.data(target, this.propertyName);
            return (inst ? inst.selectedDates : []);
        },
    
        /* Set the selected date(s) for a datepicker.
           @param  target   (element) the control to examine
           @param  dates    (CDate or number or string or [] of these) the selected date(s)
           @param  endDate  (CDate or number or string) the ending date for a range (optional)
           @param  keyUp    (boolean, internal) true if coming from keyUp processing
           @param  setOpt   (boolean, internal) true if coming from option processing */
        _setDatePlugin: function(target, dates, endDate, keyUp, setOpt) {
            var inst = $.data(target, this.propertyName);
            if (inst) {
                if (!$.isArray(dates)) {
                    dates = [dates];
                    if (endDate) {
                        dates.push(endDate);
                    }
                }
                var minDate = inst.get('minDate');
                var maxDate = inst.get('maxDate');
                var curDate = inst.selectedDates[0];
                inst.selectedDates = [];
                for (var i = 0; i < dates.length; i++) {
                    var date = plugin.determineDate(
                        dates[i], null, curDate, inst.options.dateFormat, inst.getConfig());
                    if (date) {
                        if ((!minDate || date.getTime() >= minDate.getTime()) &&
                                (!maxDate || date.getTime() <= maxDate.getTime())) {
                            var found = false;
                            for (var j = 0; j < inst.selectedDates.length; j++) {
                                if (inst.selectedDates[j].getTime() == date.getTime()) {
                                    found = true;
                                    break;
                                }
                            }
                            if (!found) {
                                inst.selectedDates.push(date);
                            }
                        }
                    }
                }
                inst.selectedDates.splice(inst.options.multiSelect ||
                    (inst.options.rangeSelect ? 2 : 1), inst.selectedDates.length);
                if (inst.options.rangeSelect) {
                    switch (inst.selectedDates.length) {
                        case 1: inst.selectedDates[1] = inst.selectedDates[0]; break;
                        case 2: inst.selectedDates[1] =
                            (inst.selectedDates[0].getTime() > inst.selectedDates[1].getTime() ?
                            inst.selectedDates[0] : inst.selectedDates[1]); break;
                    }
                    inst.pickingRange = false;
                }
                inst.prevDate = (inst.drawDate ? plugin.newDate(inst.drawDate) : null);
                inst.drawDate = this._checkMinMax(plugin.newDate(inst.selectedDates[0] ||
                    inst.get('defaultDate') || plugin.today()), inst);
                if (!setOpt) {
                    this._update(target);
                    this._updateInput(target, keyUp);
                }
            }
        },
    
        /* Determine whether a date is selectable for this datepicker.
           @param  target  (element) the control to check
           @param  date    (Date or string or number) the date to check
           @return  (boolean) true if selectable, false if not */
        _isSelectablePlugin: function(target, date) {
            var inst = $.data(target, this.propertyName);
            if (!inst) {
                return false;
            }
            date = plugin.determineDate(date, inst.selectedDates[0] || this.today(), null,
                inst.options.dateFormat, inst.getConfig());
            return this._isSelectable(target, date, inst.options.onDate,
                inst.get('minDate'), inst.get('maxDate'));
        },
    
        /* Internally determine whether a date is selectable for this datepicker.
           @param  target   (element) the control to check
           @param  date     (Date) the date to check
           @param  onDate   (function or boolean) any onDate callback or callback.selectable
           @param  mindate  (Date) the minimum allowed date
           @param  maxdate  (Date) the maximum allowed date
           @return  (boolean) true if selectable, false if not */
        _isSelectable: function(target, date, onDate, minDate, maxDate) {
            var dateInfo = (typeof onDate == 'boolean' ? {selectable: onDate} :
                (!$.isFunction(onDate) ? {} : onDate.apply(target, [date, true])));
            return (dateInfo.selectable != false) &&
                (!minDate || date.getTime() >= minDate.getTime()) &&
                (!maxDate || date.getTime() <= maxDate.getTime());
        },
    
        /* Perform a named action for a datepicker.
           @param  target  (element) the control to affect
           @param  action  (string) the name of the action */
        _performActionPlugin: function(target, action) {
            var inst = $.data(target, this.propertyName);
            if (inst && !this._isDisabledPlugin(target)) {
                var commands = inst.options.commands;
                if (commands[action] && commands[action].enabled.apply(target, [inst])) {
                    commands[action].action.apply(target, [inst]);
                }
            }
        },
    
        /* Set the currently shown month, defaulting to today's.
           @param  target  (element) the control to affect
           @param  year    (number) the year to show (optional)
           @param  month   (number) the month to show (1-12) (optional)
           @param  day     (number) the day to show (optional) */
        _showMonthPlugin: function(target, year, month, day) {
            var inst = $.data(target, this.propertyName);
            if (inst && (day != null ||
                    (inst.drawDate.getFullYear() != year || inst.drawDate.getMonth() + 1 != month))) {
                inst.prevDate = plugin.newDate(inst.drawDate);
                var show = this._checkMinMax((year != null ?
                    plugin.newDate(year, month, 1) : plugin.today()), inst);
                inst.drawDate = plugin.newDate(show.getFullYear(), show.getMonth() + 1, 
                    (day != null ? day : Math.min(inst.drawDate.getDate(),
                    plugin.daysInMonth(show.getFullYear(), show.getMonth() + 1))));
                this._update(target);
            }
        },
    
        /* Adjust the currently shown month.
           @param  target  (element) the control to affect
           @param  offset  (number) the number of months to change by */
        _changeMonthPlugin: function(target, offset) {
            var inst = $.data(target, this.propertyName);
            if (inst) {
                var date = plugin.add(plugin.newDate(inst.drawDate), offset, 'm');
                this._showMonthPlugin(target, date.getFullYear(), date.getMonth() + 1);
            }
        },
    
        /* Adjust the currently shown day.
           @param  target  (element) the control to affect
           @param  offset  (number) the number of days to change by */
        _changeDayPlugin: function(target, offset) {
            var inst = $.data(target, this.propertyName);
            if (inst) {
                var date = plugin.add(plugin.newDate(inst.drawDate), offset, 'd');
                this._showMonthPlugin(target, date.getFullYear(), date.getMonth() + 1, date.getDate());
            }
        },
    
        /* Restrict a date to the minimum/maximum specified.
           @param  date  (CDate) the date to check
           @param  inst  (object) the current instance settings */
        _checkMinMax: function(date, inst) {
            var minDate = inst.get('minDate');
            var maxDate = inst.get('maxDate');
            date = (minDate && date.getTime() < minDate.getTime() ? plugin.newDate(minDate) : date);
            date = (maxDate && date.getTime() > maxDate.getTime() ? plugin.newDate(maxDate) : date);
            return date;
        },
    
        /* Retrieve the date associated with an entry in the datepicker.
           @param  target  (element) the control to examine
           @param  elem    (element) the selected datepicker element
           @return  (CDate) the corresponding date, or null */
        _retrieveDatePlugin: function(target, elem) {
            var inst = $.data(target, this.propertyName);
            return (!inst ? null : this._normaliseDate(
                new Date(parseInt(elem.className.replace(/^.*dp(-?\d+).*$/, '$1'), 10))));
        },
    
        /* Select a date for this datepicker.
           @param  target  (element) the control to examine
           @param  elem    (element) the selected datepicker element */
        _selectDatePlugin: function(target, elem) {
            var inst = $.data(target, this.propertyName);
            if (inst && !this._isDisabledPlugin(target)) {
                var date = this._retrieveDatePlugin(target, elem);
                if (inst.options.multiSelect) {
                    var found = false;
                    for (var i = 0; i < inst.selectedDates.length; i++) {
                        if (date.getTime() == inst.selectedDates[i].getTime()) {
                            inst.selectedDates.splice(i, 1);
                            found = true;
                            break;
                        }
                    }
                    if (!found && inst.selectedDates.length < inst.options.multiSelect) {
                        inst.selectedDates.push(date);
                    }
                }
                else if (inst.options.rangeSelect) {
                    if (inst.pickingRange) {
                        inst.selectedDates[1] = date;
                    }
                    else {
                        inst.selectedDates = [date, date];
                    }
                    inst.pickingRange = !inst.pickingRange;
                }
                else {
                    inst.selectedDates = [date];
                }
                inst.prevDate = plugin.newDate(date);
                this._updateInput(target);
                if (inst.inline || inst.pickingRange || inst.selectedDates.length <
                        (inst.options.multiSelect || (inst.options.rangeSelect ? 2 : 1))) {
                    this._update(target);
                }
                else {
                    this._hidePlugin(target);
                }
            }
        },
    
        /* Generate the datepicker content for this control.
           @param  target  (element) the control to affect
           @param  inst    (object) the current instance settings
           @return  (jQuery) the datepicker content */
        _generateContent: function(target, inst) {
            var monthsToShow = inst.options.monthsToShow;
            monthsToShow = ($.isArray(monthsToShow) ? monthsToShow : [1, monthsToShow]);
            inst.drawDate = this._checkMinMax(
                inst.drawDate || inst.get('defaultDate') || plugin.today(), inst);
            var drawDate = plugin._applyMonthsOffset(plugin.newDate(inst.drawDate), inst);
            // Generate months
            var monthRows = '';
            for (var row = 0; row < monthsToShow[0]; row++) {
                var months = '';
                for (var col = 0; col < monthsToShow[1]; col++) {
                    months += this._generateMonth(target, inst, drawDate.getFullYear(),
                        drawDate.getMonth() + 1, inst.options.renderer, (row == 0 && col == 0));
                    plugin.add(drawDate, 1, 'm');
                }
                monthRows += this._prepare(inst.options.renderer.monthRow, inst).replace(/\{months\}/, months);
            }
            var picker = this._prepare(inst.options.renderer.picker, inst).replace(/\{months\}/, monthRows).
                replace(/\{weekHeader\}/g, this._generateDayHeaders(inst, inst.options.renderer));
            // Add commands
            var addCommand = function(type, open, close, name, classes) {
                if (picker.indexOf('{' + type + ':' + name + '}') == -1) {
                    return;
                }
                var command = inst.options.commands[name];
                var date = (inst.options.commandsAsDateFormat ? command.date.apply(target, [inst]) : null);
                picker = picker.replace(new RegExp('\\{' + type + ':' + name + '\\}', 'g'),
                    '<' + open +
                    (command.status ? ' title="' + inst.options[command.status] + '"' : '') +
                    ' class="' + inst.options.renderer.commandClass + ' ' +
                    inst.options.renderer.commandClass + '-' + name + ' ' + classes +
                    (command.enabled(inst) ? '' : ' ' + inst.options.renderer.disabledClass) + '">' +
                    (date ? plugin.formatDate(inst.options[command.text], date, inst.getConfig()) :
                    inst.options[command.text]) + '</' + close + '>');
            };
            for (var name in inst.options.commands) {
                addCommand('button', 'button type="button"', 'button', name,
                    inst.options.renderer.commandButtonClass);
                addCommand('link', 'a href="javascript:void(0)"', 'a', name,
                    inst.options.renderer.commandLinkClass);
            }
            picker = $(picker);
            if (monthsToShow[1] > 1) {
                var count = 0;
                $(inst.options.renderer.monthSelector, picker).each(function() {
                    var nth = ++count % monthsToShow[1];
                    $(this).addClass(nth == 1 ? 'first' : (nth == 0 ? 'last' : ''));
                });
            }
            // Add datepicker behaviour
            var self = this;
            picker.find(inst.options.renderer.daySelector + ' a').hover(
                    function() { $(this).addClass(inst.options.renderer.highlightedClass); },
                    function() {
                        (inst.inline ? $(this).parents('.' + self.markerClassName) : inst.div).
                            find(inst.options.renderer.daySelector + ' a').
                            removeClass(inst.options.renderer.highlightedClass);
                    }).
                click(function() {
                    self._selectDatePlugin(target, this);
                }).end().
                find('select.' + this._monthYearClass + ':not(.' + this._anyYearClass + ')').
                change(function() {
                    var monthYear = $(this).val().split('/');
                    self._showMonthPlugin(target, parseInt(monthYear[1], 10), parseInt(monthYear[0], 10));
                }).end().
                find('select.' + this._anyYearClass).click(function() {
                    $(this).css('visibility', 'hidden').
                        next('input').css({left: this.offsetLeft, top: this.offsetTop,
                        width: this.offsetWidth, height: this.offsetHeight}).show().focus();
                }).end().
                find('input.' + self._monthYearClass).change(function() {
                    try {
                        var year = parseInt($(this).val(), 10);
                        year = (isNaN(year) ? inst.drawDate.getFullYear() : year);
                        self._showMonthPlugin(target, year, inst.drawDate.getMonth() + 1, inst.drawDate.getDate());
                    }
                    catch (e) {
                        alert(e);
                    }
                }).keydown(function(event) {
                    if (event.keyCode == 13) { // Enter
                        $(event.target).change();
                    }
                    else if (event.keyCode == 27) { // Escape
                        $(event.target).hide().prev('select').css('visibility', 'visible');
                        inst.target.focus();
                    }
                });
            // Add command behaviour
            picker.find('.' + inst.options.renderer.commandClass).click(function() {
                    if (!$(this).hasClass(inst.options.renderer.disabledClass)) {
                        var action = this.className.replace(
                            new RegExp('^.*' + inst.options.renderer.commandClass + '-([^ ]+).*$'), '$1');
                        plugin._performActionPlugin(target, action);
                    }
                });
            // Add classes
            if (inst.options.isRTL) {
                picker.addClass(inst.options.renderer.rtlClass);
            }
            if (monthsToShow[0] * monthsToShow[1] > 1) {
                picker.addClass(inst.options.renderer.multiClass);
            }
            if (inst.options.pickerClass) {
                picker.addClass(inst.options.pickerClass);
            }
            // Resize
            $('body').append(picker);
            var width = 0;
            picker.find(inst.options.renderer.monthSelector).each(function() {
                width += $(this).outerWidth();
            });
            picker.width(width / monthsToShow[0]);
            // Pre-show customisation
            if ($.isFunction(inst.options.onShow)) {
                inst.options.onShow.apply(target, [picker, inst]);
            }
            return picker;
        },
    
        /* Generate the content for a single month.
           @param  target    (element) the control to affect
           @param  inst      (object) the current instance settings
           @param  year      (number) the year to generate
           @param  month     (number) the month to generate
           @param  renderer  (object) the rendering templates
           @param  first     (boolean) true if first of multiple months
           @return  (string) the month content */
        _generateMonth: function(target, inst, year, month, renderer, first) {
            var daysInMonth = plugin.daysInMonth(year, month);
            var monthsToShow = inst.options.monthsToShow;
            monthsToShow = ($.isArray(monthsToShow) ? monthsToShow : [1, monthsToShow]);
            var fixedWeeks = inst.options.fixedWeeks || (monthsToShow[0] * monthsToShow[1] > 1);
            var firstDay = inst.options.firstDay;
            var leadDays = (plugin.newDate(year, month, 1).getDay() - firstDay + 7) % 7;
            var numWeeks = (fixedWeeks ? 6 : Math.ceil((leadDays + daysInMonth) / 7));
            var selectOtherMonths = inst.options.selectOtherMonths && inst.options.showOtherMonths;
            var minDate = (inst.pickingRange ? inst.selectedDates[0] : inst.get('minDate'));
            var maxDate = inst.get('maxDate');
            var showWeeks = renderer.week.indexOf('{weekOfYear}') > -1;
            var today = plugin.today();
            var drawDate = plugin.newDate(year, month, 1);
            plugin.add(drawDate, -leadDays - (fixedWeeks && (drawDate.getDay() == firstDay) ? 7 : 0), 'd');
            var ts = drawDate.getTime();
            // Generate weeks
            var weeks = '';
            for (var week = 0; week < numWeeks; week++) {
                var weekOfYear = (!showWeeks ? '' : '<span class="dp' + ts + '">' +
                    ($.isFunction(inst.options.calculateWeek) ? inst.options.calculateWeek(drawDate) : 0) + '</span>');
                var days = '';
                for (var day = 0; day < 7; day++) {
                    var selected = false;
                    if (inst.options.rangeSelect && inst.selectedDates.length > 0) {
                        selected = (drawDate.getTime() >= inst.selectedDates[0] &&
                            drawDate.getTime() <= inst.selectedDates[1]);
                    }
                    else {
                        for (var i = 0; i < inst.selectedDates.length; i++) {
                            if (inst.selectedDates[i].getTime() == drawDate.getTime()) {
                                selected = true;
                                break;
                            }
                        }
                    }
                    var dateInfo = (!$.isFunction(inst.options.onDate) ? {} :
                        inst.options.onDate.apply(target, [drawDate, drawDate.getMonth() + 1 == month]));
                    var selectable = (selectOtherMonths || drawDate.getMonth() + 1 == month) &&
                        this._isSelectable(target, drawDate, dateInfo.selectable, minDate, maxDate);
                    days += this._prepare(renderer.day, inst).replace(/\{day\}/g,
                        (selectable ? '<a href="javascript:void(0)"' : '<span') +
                        ' class="dp' + ts + ' ' + (dateInfo.dateClass || '') +
                        (selected && (selectOtherMonths || drawDate.getMonth() + 1 == month) ?
                        ' ' + renderer.selectedClass : '') +
                        (selectable ? ' ' + renderer.defaultClass : '') +
                        ((drawDate.getDay() || 7) < 6 ? '' : ' ' + renderer.weekendClass) +
                        (drawDate.getMonth() + 1 == month ? '' : ' ' + renderer.otherMonthClass) +
                        (drawDate.getTime() == today.getTime() && (drawDate.getMonth() + 1) == month ?
                        ' ' + renderer.todayClass : '') +
                        (drawDate.getTime() == inst.drawDate.getTime() && (drawDate.getMonth() + 1) == month ?
                        ' ' + renderer.highlightedClass : '') + '"' +
                        (dateInfo.title || (inst.options.dayStatus && selectable) ? ' title="' +
                        (dateInfo.title || plugin.formatDate(
                        inst.options.dayStatus, drawDate, inst.getConfig())) + '"' : '') + '>' +
                        (inst.options.showOtherMonths || (drawDate.getMonth() + 1) == month ?
                        dateInfo.content || drawDate.getDate() : '&nbsp;') +
                        (selectable ? '</a>' : '</span>'));
                    plugin.add(drawDate, 1, 'd');
                    ts = drawDate.getTime();
                }
                weeks += this._prepare(renderer.week, inst).replace(/\{days\}/g, days).
                    replace(/\{weekOfYear\}/g, weekOfYear);
            }
            var monthHeader = this._prepare(renderer.month, inst).match(/\{monthHeader(:[^\}]+)?\}/);
            monthHeader = (monthHeader[0].length <= 13 ? 'MM yyyy' :
                monthHeader[0].substring(13, monthHeader[0].length - 1));
            monthHeader = (first ? this._generateMonthSelection(
                inst, year, month, minDate, maxDate, monthHeader, renderer) :
                plugin.formatDate(monthHeader, plugin.newDate(year, month, 1), inst.getConfig()));
            var weekHeader = this._prepare(renderer.weekHeader, inst).
                replace(/\{days\}/g, this._generateDayHeaders(inst, renderer));
            return this._prepare(renderer.month, inst).replace(/\{monthHeader(:[^\}]+)?\}/g, monthHeader).
                replace(/\{weekHeader\}/g, weekHeader).replace(/\{weeks\}/g, weeks);
        },
    
        /* Generate the HTML for the day headers.
           @param  inst      (object) the current instance settings
           @param  renderer  (object) the rendering templates
           @return  (string) a week's worth of day headers */
        _generateDayHeaders: function(inst, renderer) {
            var header = '';
            for (var day = 0; day < 7; day++) {
                var dow = (day + inst.options.firstDay) % 7;
                header += this._prepare(renderer.dayHeader, inst).replace(/\{day\}/g,
                    '<span class="' + this._curDoWClass + dow + '" title="' +
                    inst.options.dayNames[dow] + '">' + inst.options.dayNamesMin[dow] + '</span>');
            }
            return header;
        },
    
        /* Generate selection controls for month.
           @param  inst         (object) the current instance settings
           @param  year         (number) the year to generate
           @param  month        (number) the month to generate
           @param  minDate      (CDate) the minimum date allowed
           @param  maxDate      (CDate) the maximum date allowed
           @param  monthHeader  (string) the month/year format
           @return  (string) the month selection content */
        _generateMonthSelection: function(inst, year, month, minDate, maxDate, monthHeader) {
            if (!inst.options.changeMonth) {
                return plugin.formatDate(
                    monthHeader, plugin.newDate(year, month, 1), inst.getConfig());
            }
            // Months
            var monthNames = inst.options['monthNames' + (monthHeader.match(/mm/i) ? '' : 'Short')];
            var html = monthHeader.replace(/m+/i, '\\x2E').replace(/y+/i, '\\x2F');
            var selector = '<select class="' + this._monthYearClass +
                '" title="' + inst.options.monthStatus + '">';
            for (var m = 1; m <= 12; m++) {
                if ((!minDate || plugin.newDate(year, m, plugin.daysInMonth(year, m)).
                        getTime() >= minDate.getTime()) &&
                        (!maxDate || plugin.newDate(year, m, 1).getTime() <= maxDate.getTime())) {
                    selector += '<option value="' + m + '/' + year + '"' +
                        (month == m ? ' selected="selected"' : '') + '>' +
                        monthNames[m - 1] + '</option>';
                }
            }
            selector += '</select>';
            html = html.replace(/\\x2E/, selector);
            // Years
            var yearRange = inst.options.yearRange;
            if (yearRange == 'any') {
                selector = '<select class="' + this._monthYearClass + ' ' + this._anyYearClass +
                    '" title="' + inst.options.yearStatus + '">' +
                    '<option>' + year + '</option></select>' +
                    '<input class="' + this._monthYearClass + ' ' + this._curMonthClass +
                    month + '" value="' + year + '">';
            }
            else {
                yearRange = yearRange.split(':');
                var todayYear = plugin.today().getFullYear();
                var start = (yearRange[0].match('c[+-].*') ? year + parseInt(yearRange[0].substring(1), 10) :
                    ((yearRange[0].match('[+-].*') ? todayYear : 0) + parseInt(yearRange[0], 10)));
                var end = (yearRange[1].match('c[+-].*') ? year + parseInt(yearRange[1].substring(1), 10) :
                    ((yearRange[1].match('[+-].*') ? todayYear : 0) + parseInt(yearRange[1], 10)));
                selector = '<select class="' + this._monthYearClass +
                    '" title="' + inst.options.yearStatus + '">';
                start = plugin.add(plugin.newDate(start + 1, 1, 1), -1, 'd');
                end = plugin.newDate(end, 1, 1);
                var addYear = function(y) {
                    if (y != 0) {
                        selector += '<option value="' + month + '/' + y + '"' +
                            (year == y ? ' selected="selected"' : '') + '>' + y + '</option>';
                    }
                };
                if (start.getTime() < end.getTime()) {
                    start = (minDate && minDate.getTime() > start.getTime() ? minDate : start).getFullYear();
                    end = (maxDate && maxDate.getTime() < end.getTime() ? maxDate : end).getFullYear();
                    for (var y = start; y <= end; y++) {
                        addYear(y);
                    }
                }
                else {
                    start = (maxDate && maxDate.getTime() < start.getTime() ? maxDate : start).getFullYear();
                    end = (minDate && minDate.getTime() > end.getTime() ? minDate : end).getFullYear();
                    for (var y = start; y >= end; y--) {
                        addYear(y);
                    }
                }
                selector += '</select>';
            }
            html = html.replace(/\\x2F/, selector);
            return html;
        },
    
        /* Prepare a render template for use.
           Exclude popup/inline sections that are not applicable.
           Localise text of the form: {l10n:name}.
           @param  text  (string) the text to localise
           @param  inst  (object) the current instance settings
           @return  (string) the localised text */
        _prepare: function(text, inst) {
            var replaceSection = function(type, retain) {
                while (true) {
                    var start = text.indexOf('{' + type + ':start}');
                    if (start == -1) {
                        return;
                    }
                    var end = text.substring(start).indexOf('{' + type + ':end}');
                    if (end > -1) {
                        text = text.substring(0, start) +
                            (retain ? text.substr(start + type.length + 8, end - type.length - 8) : '') +
                            text.substring(start + end + type.length + 6);
                    }
                }
            };
            replaceSection('inline', inst.inline);
            replaceSection('popup', !inst.inline);
            var pattern = /\{l10n:([^\}]+)\}/;
            var matches = null;
            while (matches = pattern.exec(text)) {
                text = text.replace(matches[0], inst.options[matches[1]]);
            }
            return text;
        }
    });
    
    // The list of commands that return values and don't permit chaining
    var getters = ['getDate', 'isDisabled', 'isSelectable', 'retrieveDate'];
    
    /* Determine whether a command is a getter and doesn't permit chaining.
       @param  command    (string, optional) the command to run
       @param  otherArgs  ([], optional) any other arguments for the command
       @return  true if the command is a getter, false if not */
    function isNotChained(command, otherArgs) {
        if (command == 'option' && (otherArgs.length == 0 ||
                (otherArgs.length == 1 && typeof otherArgs[0] == 'string'))) {
            return true;
        }
        return $.inArray(command, getters) > -1;
    }
    
    /* Attach the datepicker functionality to a jQuery selection.
       @param  options  (object) the new settings to use for these instances (optional) or
                        (string) the command to run (optional)
       @return  (jQuery) for chaining further calls or
                (any) getter value */
    $.fn.datepick = function(options) {
        var otherArgs = Array.prototype.slice.call(arguments, 1);
        if (isNotChained(options, otherArgs)) {
            return plugin['_' + options + 'Plugin'].apply(plugin, [this[0]].concat(otherArgs));
        }
        return this.each(function() {
            if (typeof options == 'string') {
                if (!plugin['_' + options + 'Plugin']) {
                    throw 'Unknown command: ' + options;
                }
                plugin['_' + options + 'Plugin'].apply(plugin, [this].concat(otherArgs));
            }
            else {
                plugin._attachPlugin(this, options || {});
            }
        });
    };
    
    /* Initialise the datepicker functionality. */
    var plugin = $.datepick = new Datepicker(); // Singleton instance
    
    $(function() {
        $(document).mousedown(plugin._checkExternalClick).
            resize(function() { plugin._hidePlugin(plugin.curInst); });
    });
    
    })(jQuery);
    