jquery-ui/ui/jquery.ui.datepicker.js

/*
 * jQuery UI Datepicker @VERSION
 *
 * Copyright 2011, AUTHORS.txt (http://jqueryui.com/about)
 * Dual licensed under the MIT or GPL Version 2 licenses.
 * http://jquery.org/license
 *
 * http://docs.jquery.com/UI/Datepicker
 *
 * Depends:
 *	jquery.ui.core.js
 */
(function( $, undefined ) {

$.extend($.ui, { datepicker: { version: "@VERSION" } });

var PROP_NAME = 'datepicker';
var dpuuid = new Date().getTime();
var instActive;

/* Date picker manager.
   Use the singleton instance of this class, $.datepicker, to interact with the date picker.
   Settings for (groups of) date pickers are maintained in an instance object,
   allowing multiple different settings on the same page. */

function Datepicker() {
	this.debug = false; // Change this to true to start debugging
	this._curInst = null; // The current instance in use
	this._keyEvent = false; // If the last event was a key event
	this._disabledInputs = []; // List of date picker inputs that have been disabled
	this._datepickerShowing = false; // True if the popup picker is showing , false if not
	this._inDialog = false; // True if showing within a "dialog", false if not
	this._mainDivId = 'ui-datepicker-div'; // The ID of the main datepicker division
	this._inlineClass = 'ui-datepicker-inline'; // The name of the inline marker class
	this._appendClass = 'ui-datepicker-append'; // The name of the append marker class
	this._triggerClass = 'ui-datepicker-trigger'; // The name of the trigger marker class
	this._dialogClass = 'ui-datepicker-dialog'; // The name of the dialog marker class
	this._disableClass = 'ui-datepicker-disabled'; // The name of the disabled covering marker class
	this._unselectableClass = 'ui-datepicker-unselectable'; // The name of the unselectable cell marker class
	this._currentClass = 'ui-datepicker-current-day'; // The name of the current day marker class
	this._dayOverClass = 'ui-datepicker-days-cell-over'; // The name of the day hover marker class
	this.regional = []; // Available regional settings, indexed by language code
	this.regional[''] = { // Default regional settings
		closeText: 'Done', // Display text for close link
		prevText: 'Prev', // Display text for previous month link
		nextText: 'Next', // Display text for next month link
		currentText: 'Today', // Display text for current month link
		monthNames: ['January','February','March','April','May','June',
			'July','August','September','October','November','December'], // Names of months for drop-down and formatting
		monthNamesShort: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'], // For formatting
		dayNames: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'], // For formatting
		dayNamesShort: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'], // For formatting
		dayNamesMin: ['Su','Mo','Tu','We','Th','Fr','Sa'], // Column headings for days starting at Sunday
		weekHeader: 'Wk', // Column header for week of the year
		dateFormat: 'mm/dd/yy', // See format options on parseDate
		firstDay: 0, // The first day of the week, Sun = 0, Mon = 1, ...
		isRTL: false, // True if right-to-left language, false if left-to-right
		showMonthAfterYear: false, // True if the year select precedes month, false for month then year
		yearSuffix: '' // Additional text to append to the year in the month headers
	};
	this._defaults = { // Global defaults for all the date picker instances
		showOn: 'focus', // 'focus' for popup on focus,
			// 'button' for trigger button, or 'both' for either
		showAnim: 'fadeIn', // Name of jQuery animation for popup
		showOptions: {}, // Options for enhanced animations
		defaultDate: null, // Used when field is blank: actual date,
			// +/-number for offset from today, null for today
		appendText: '', // Display text following the input box, e.g. showing the format
		buttonText: '...', // Text for trigger button
		buttonImage: '', // URL for trigger button image
		buttonImageOnly: false, // True if the image appears alone, false if it appears on a button
		hideIfNoPrevNext: false, // True to hide next/previous month links
			// if not applicable, false to just disable them
		navigationAsDateFormat: false, // True if date formatting applied to prev/today/next links
		gotoCurrent: false, // True if today link goes back to current selection instead
		changeMonth: false, // True if month can be selected directly, false if only prev/next
		changeYear: false, // True if year can be selected directly, false if only prev/next
		yearRange: 'c-10:c+10', // Range of years to display in drop-down,
			// either relative to today's year (-nn:+nn), relative to currently displayed year
			// (c-nn:c+nn), absolute (nnnn:nnnn), or a combination of the above (nnnn:-n)
		showOtherMonths: false, // True to show dates in other months, false to leave blank
		selectOtherMonths: false, // True to allow selection of dates in other months, false for unselectable
		showWeek: false, // True to show week of the year, false to not show it
		calculateWeek: this.iso8601Week, // How to calculate the week of the year,
			// takes a Date and returns the number of the week for it
		shortYearCutoff: '+10', // Short year values < this are in the current century,
			// > this are in the previous century,
			// string value starting with '+' for current year + value
		minDate: null, // The earliest selectable date, or null for no limit
		maxDate: null, // The latest selectable date, or null for no limit
		duration: 'fast', // Duration of display/closure
		beforeShowDay: null, // Function that takes a date and returns an array with
			// [0] = true if selectable, false if not, [1] = custom CSS class name(s) or '',
			// [2] = cell title (optional), e.g. $.datepicker.noWeekends
		beforeShow: null, // Function that takes an input field and
			// returns a set of custom settings for the date picker
		onSelect: null, // Define a callback function when a date is selected
		onChangeMonthYear: null, // Define a callback function when the month or year is changed
		onClose: null, // Define a callback function when the datepicker is closed
		numberOfMonths: 1, // Number of months to show at a time
		showCurrentAtPos: 0, // The position in multipe months at which to show the current month (starting at 0)
		stepMonths: 1, // Number of months to step back/forward
		stepBigMonths: 12, // Number of months to step back/forward for the big links
		altField: '', // Selector for an alternate field to store selected dates into
		altFormat: '', // The date format to use for the alternate field
		constrainInput: true, // The input is constrained by the current date format
		showButtonPanel: false, // True to show button panel, false to not show it
		autoSize: false, // True to size the input for the date format, false to leave as is
		disabled: false // The initial disabled state
	};
	$.extend(this._defaults, this.regional['']);
	this.dpDiv = bindHover($('<div id="' + this._mainDivId + '" class="ui-datepicker ui-widget ui-widget-content ui-helper-clearfix ui-corner-all"></div>'));
}

$.extend(Datepicker.prototype, {
	/* Class name added to elements to indicate already configured with a date picker. */
	markerClassName: 'hasDatepicker',
	
	//Keep track of the maximum number of rows displayed (see #7043)
	maxRows: 4,

	/* Debug logging (if enabled). */
	log: function () {
		if (this.debug)
			console.log.apply('', arguments);
	},
	
	// TODO rename to "widget" when switching to widget factory
	_widgetDatepicker: function() {
		return this.dpDiv;
	},

	/* Override the default settings for all instances of the date picker.
	   @param  settings  object - the new settings to use as defaults (anonymous object)
	   @return the manager object */
	setDefaults: function(settings) {
		extendRemove(this._defaults, settings || {});
		return this;
	},

	/* Attach the date picker to a jQuery selection.
	   @param  target    element - the target input field or division or span
	   @param  settings  object - the new settings to use for this date picker instance (anonymous) */
	_attachDatepicker: function(target, settings) {
		// check for settings on the control itself - in namespace 'date:'
		var inlineSettings = null;
		for (var attrName in this._defaults) {
			var attrValue = target.getAttribute('date:' + attrName);
			if (attrValue) {
				inlineSettings = inlineSettings || {};
				try {
					inlineSettings[attrName] = eval(attrValue);
				} catch (err) {
					inlineSettings[attrName] = attrValue;
				}
			}
		}
		var nodeName = target.nodeName.toLowerCase();
		var inline = (nodeName == 'div' || nodeName == 'span');
		if (!target.id) {
			this.uuid += 1;
			target.id = 'dp' + this.uuid;
		}
		var inst = this._newInst($(target), inline);
		inst.settings = $.extend({}, settings || {}, inlineSettings || {});
		if (nodeName == 'input') {
			this._connectDatepicker(target, inst);
		} else if (inline) {
			this._inlineDatepicker(target, inst);
		}
	},

	/* Create a new instance object. */
	_newInst: function(target, inline) {
		var id = target[0].id.replace(/([^A-Za-z0-9_-])/g, '\\\\$1'); // escape jQuery meta chars
		return {id: id, input: target, // associated target
			selectedDay: 0, selectedMonth: 0, selectedYear: 0, // current selection
			drawMonth: 0, drawYear: 0, // month being drawn
			inline: inline, // is datepicker inline or not
			dpDiv: (!inline ? this.dpDiv : // presentation div
			bindHover($('<div class="' + this._inlineClass + ' ui-datepicker ui-widget ui-widget-content ui-helper-clearfix ui-corner-all"></div>')))};
	},

	/* Attach the date picker to an input field. */
	_connectDatepicker: function(target, inst) {
		var input = $(target);
		inst.append = $([]);
		inst.trigger = $([]);
		if (input.hasClass(this.markerClassName))
			return;
		this._attachments(input, inst);
		input.addClass(this.markerClassName).keydown(this._doKeyDown).
			keypress(this._doKeyPress).keyup(this._doKeyUp).
			bind("setData.datepicker", function(event, key, value) {
				inst.settings[key] = value;
			}).bind("getData.datepicker", function(event, key) {
				return this._get(inst, key);
			});
		this._autoSize(inst);
		$.data(target, PROP_NAME, inst);
		//If disabled option is true, disable the datepicker once it has been attached to the input (see ticket #5665)
		if( inst.settings.disabled ) {
			this._disableDatepicker( target );
		}
	},

	/* Make attachments based on settings. */
	_attachments: function(input, inst) {
		var appendText = this._get(inst, 'appendText');
		var isRTL = this._get(inst, 'isRTL');
		if (inst.append)
			inst.append.remove();
		if (appendText) {
			inst.append = $('<span class="' + this._appendClass + '">' + appendText + '</span>');
			input[isRTL ? 'before' : 'after'](inst.append);
		}
		input.unbind('focus', this._showDatepicker);
		if (inst.trigger)
			inst.trigger.remove();
		var showOn = this._get(inst, 'showOn');
		if (showOn == 'focus' || showOn == 'both') // pop-up date picker when in the marked field
			input.focus(this._showDatepicker);
		if (showOn == 'button' || showOn == 'both') { // pop-up date picker when button clicked
			var buttonText = this._get(inst, 'buttonText');
			var buttonImage = this._get(inst, 'buttonImage');
			inst.trigger = $(this._get(inst, 'buttonImageOnly') ?
				$('<img/>').addClass(this._triggerClass).
					attr({ src: buttonImage, alt: buttonText, title: buttonText }) :
				$('<button type="button"></button>').addClass(this._triggerClass).
					html(buttonImage == '' ? buttonText : $('<img/>').attr(
					{ src:buttonImage, alt:buttonText, title:buttonText })));
			input[isRTL ? 'before' : 'after'](inst.trigger);
			inst.trigger.click(function() {
				if ($.datepicker._datepickerShowing && $.datepicker._lastInput == input[0])
					$.datepicker._hideDatepicker();
				else if ($.datepicker._datepickerShowing && $.datepicker._lastInput != input[0]) {
					$.datepicker._hideDatepicker(); 
					$.datepicker._showDatepicker(input[0]);
				} else
					$.datepicker._showDatepicker(input[0]);
				return false;
			});
		}
	},

	/* Apply the maximum length for the date format. */
	_autoSize: function(inst) {
		if (this._get(inst, 'autoSize') && !inst.inline) {
			var date = new Date(2009, 12 - 1, 20); // Ensure double digits
			var dateFormat = this._get(inst, '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(this._get(inst, (dateFormat.match(/MM/) ?
					'monthNames' : 'monthNamesShort'))));
				date.setDate(findMax(this._get(inst, (dateFormat.match(/DD/) ?
					'dayNames' : 'dayNamesShort'))) + 20 - date.getDay());
			}
			inst.input.attr('size', this._formatDate(inst, date).length);
		}
	},

	/* Attach an inline date picker to a div. */
	_inlineDatepicker: function(target, inst) {
		var divSpan = $(target);
		if (divSpan.hasClass(this.markerClassName))
			return;
		divSpan.addClass(this.markerClassName).append(inst.dpDiv).
			bind("setData.datepicker", function(event, key, value){
				inst.settings[key] = value;
			}).bind("getData.datepicker", function(event, key){
				return this._get(inst, key);
			});
		$.data(target, PROP_NAME, inst);
		this._setDate(inst, this._getDefaultDate(inst), true);
		this._updateDatepicker(inst);
		this._updateAlternate(inst);
		//If disabled option is true, disable the datepicker before showing it (see ticket #5665)
		if( inst.settings.disabled ) {
			this._disableDatepicker( target );
		}
		// Set display:block in place of inst.dpDiv.show() which won't work on disconnected elements
		// http://bugs.jqueryui.com/ticket/7552 - A Datepicker created on a detached div has zero height
		inst.dpDiv.css( "display", "block" );
	},

	/* Pop-up the date picker in a "dialog" box.
	   @param  input     element - ignored
	   @param  date      string or Date - the initial date to display
	   @param  onSelect  function - the function to call when a date is selected
	   @param  settings  object - update the dialog date picker instance's settings (anonymous object)
	   @param  pos       int[2] - coordinates for the dialog's position within the screen or
	                     event - with x/y coordinates or
	                     leave empty for default (screen centre)
	   @return the manager object */
	_dialogDatepicker: function(input, date, onSelect, settings, pos) {
		var inst = this._dialogInst; // internal instance
		if (!inst) {
			this.uuid += 1;
			var id = 'dp' + this.uuid;
			this._dialogInput = $('<input type="text" id="' + id +
				'" style="position: absolute; top: -100px; width: 0px; z-index: -10;"/>');
			this._dialogInput.keydown(this._doKeyDown);
			$('body').append(this._dialogInput);
			inst = this._dialogInst = this._newInst(this._dialogInput, false);
			inst.settings = {};
			$.data(this._dialogInput[0], PROP_NAME, inst);
		}
		extendRemove(inst.settings, settings || {});
		date = (date && date.constructor == Date ? this._formatDate(inst, date) : date);
		this._dialogInput.val(date);

		this._pos = (pos ? (pos.length ? pos : [pos.pageX, pos.pageY]) : null);
		if (!this._pos) {
			var browserWidth = document.documentElement.clientWidth;
			var browserHeight = document.documentElement.clientHeight;
			var scrollX = document.documentElement.scrollLeft || document.body.scrollLeft;
			var scrollY = document.documentElement.scrollTop || document.body.scrollTop;
			this._pos = // should use actual width/height below
				[(browserWidth / 2) - 100 + scrollX, (browserHeight / 2) - 150 + scrollY];
		}

		// move input on screen for focus, but hidden behind dialog
		this._dialogInput.css('left', (this._pos[0] + 20) + 'px').css('top', this._pos[1] + 'px');
		inst.settings.onSelect = onSelect;
		this._inDialog = true;
		this.dpDiv.addClass(this._dialogClass);
		this._showDatepicker(this._dialogInput[0]);
		if ($.blockUI)
			$.blockUI(this.dpDiv);
		$.data(this._dialogInput[0], PROP_NAME, inst);
		return this;
	},

	/* Detach a datepicker from its control.
	   @param  target    element - the target input field or division or span */
	_destroyDatepicker: function(target) {
		var $target = $(target);
		var inst = $.data(target, PROP_NAME);
		if (!$target.hasClass(this.markerClassName)) {
			return;
		}
		var nodeName = target.nodeName.toLowerCase();
		$.removeData(target, PROP_NAME);
		if (nodeName == 'input') {
			inst.append.remove();
			inst.trigger.remove();
			$target.removeClass(this.markerClassName).
				unbind('focus', this._showDatepicker).
				unbind('keydown', this._doKeyDown).
				unbind('keypress', this._doKeyPress).
				unbind('keyup', this._doKeyUp);
		} else if (nodeName == 'div' || nodeName == 'span')
			$target.removeClass(this.markerClassName).empty();
	},

	/* Enable the date picker to a jQuery selection.
	   @param  target    element - the target input field or division or span */
	_enableDatepicker: function(target) {
		var $target = $(target);
		var inst = $.data(target, PROP_NAME);
		if (!$target.hasClass(this.markerClassName)) {
			return;
		}
		var nodeName = target.nodeName.toLowerCase();
		if (nodeName == 'input') {
			target.disabled = false;
			inst.trigger.filter('button').
				each(function() { this.disabled = false; }).end().
				filter('img').css({opacity: '1.0', cursor: ''});
		}
		else if (nodeName == 'div' || nodeName == 'span') {
			var inline = $target.children('.' + this._inlineClass);
			inline.children().removeClass('ui-state-disabled');
			inline.find("select.ui-datepicker-month, select.ui-datepicker-year").
				prop("disabled", false);
		}
		this._disabledInputs = $.map(this._disabledInputs,
			function(value) { return (value == target ? null : value); }); // delete entry
	},

	/* Disable the date picker to a jQuery selection.
	   @param  target    element - the target input field or division or span */
	_disableDatepicker: function(target) {
		var $target = $(target);
		var inst = $.data(target, PROP_NAME);
		if (!$target.hasClass(this.markerClassName)) {
			return;
		}
		var nodeName = target.nodeName.toLowerCase();
		if (nodeName == 'input') {
			target.disabled = true;
			inst.trigger.filter('button').
				each(function() { this.disabled = true; }).end().
				filter('img').css({opacity: '0.5', cursor: 'default'});
		}
		else if (nodeName == 'div' || nodeName == 'span') {
			var inline = $target.children('.' + this._inlineClass);
			inline.children().addClass('ui-state-disabled');
			inline.find("select.ui-datepicker-month, select.ui-datepicker-year").
				prop("disabled", true);
		}
		this._disabledInputs = $.map(this._disabledInputs,
			function(value) { return (value == target ? null : value); }); // delete entry
		this._disabledInputs[this._disabledInputs.length] = target;
	},

	/* Is the first field in a jQuery collection disabled as a datepicker?
	   @param  target    element - the target input field or division or span
	   @return boolean - true if disabled, false if enabled */
	_isDisabledDatepicker: function(target) {
		if (!target) {
			return false;
		}
		for (var i = 0; i < this._disabledInputs.length; i++) {
			if (this._disabledInputs[i] == target)
				return true;
		}
		return false;
	},

	/* Retrieve the instance data for the target control.
	   @param  target  element - the target input field or division or span
	   @return  object - the associated instance data
	   @throws  error if a jQuery problem getting data */
	_getInst: function(target) {
		try {
			return $.data(target, PROP_NAME);
		}
		catch (err) {
			throw 'Missing instance data for this datepicker';
		}
	},

	/* Update or retrieve the settings for a date picker attached to an input field or division.
	   @param  target  element - the target input field or division or span
	   @param  name    object - the new settings to update or
	                   string - the name of the setting to change or retrieve,
	                   when retrieving also 'all' for all instance settings or
	                   'defaults' for all global defaults
	   @param  value   any - the new value for the setting
	                   (omit if above is an object or to retrieve a value) */
	_optionDatepicker: function(target, name, value) {
		var inst = this._getInst(target);
		if (arguments.length == 2 && typeof name == 'string') {
			return (name == 'defaults' ? $.extend({}, $.datepicker._defaults) :
				(inst ? (name == 'all' ? $.extend({}, inst.settings) :
				this._get(inst, name)) : null));
		}
		var settings = name || {};
		if (typeof name == 'string') {
			settings = {};
			settings[name] = value;
		}
		if (inst) {
			if (this._curInst == inst) {
				this._hideDatepicker();
			}
			var date = this._getDateDatepicker(target, true);
			var minDate = this._getMinMaxDate(inst, 'min');
			var maxDate = this._getMinMaxDate(inst, 'max');
			extendRemove(inst.settings, settings);
			// reformat the old minDate/maxDate values if dateFormat changes and a new minDate/maxDate isn't provided
			if (minDate !== null && settings['dateFormat'] !== undefined && settings['minDate'] === undefined)
				inst.settings.minDate = this._formatDate(inst, minDate);
			if (maxDate !== null && settings['dateFormat'] !== undefined && settings['maxDate'] === undefined)
				inst.settings.maxDate = this._formatDate(inst, maxDate);
			this._attachments($(target), inst);
			this._autoSize(inst);
			this._setDate(inst, date);
			this._updateAlternate(inst);
			this._updateDatepicker(inst);
		}
	},

	// change method deprecated
	_changeDatepicker: function(target, name, value) {
		this._optionDatepicker(target, name, value);
	},

	/* Redraw the date picker attached to an input field or division.
	   @param  target  element - the target input field or division or span */
	_refreshDatepicker: function(target) {
		var inst = this._getInst(target);
		if (inst) {
			this._updateDatepicker(inst);
		}
	},

	/* Set the dates for a jQuery selection.
	   @param  target   element - the target input field or division or span
	   @param  date     Date - the new date */
	_setDateDatepicker: function(target, date) {
		var inst = this._getInst(target);
		if (inst) {
			this._setDate(inst, date);
			this._updateDatepicker(inst);
			this._updateAlternate(inst);
		}
	},

	/* Get the date(s) for the first entry in a jQuery selection.
	   @param  target     element - the target input field or division or span
	   @param  noDefault  boolean - true if no default date is to be used
	   @return Date - the current date */
	_getDateDatepicker: function(target, noDefault) {
		var inst = this._getInst(target);
		if (inst && !inst.inline)
			this._setDateFromField(inst, noDefault);
		return (inst ? this._getDate(inst) : null);
	},

	/* Handle keystrokes. */
	_doKeyDown: function(event) {
		var inst = $.datepicker._getInst(event.target);
		var handled = true;
		var isRTL = inst.dpDiv.is('.ui-datepicker-rtl');
		inst._keyEvent = true;
		if ($.datepicker._datepickerShowing)
			switch (event.keyCode) {
				case 9: $.datepicker._hideDatepicker();
						handled = false;
						break; // hide on tab out
				case 13: var sel = $('td.' + $.datepicker._dayOverClass + ':not(.' + 
									$.datepicker._currentClass + ')', inst.dpDiv);
						if (sel[0])
							$.datepicker._selectDay(event.target, inst.selectedMonth, inst.selectedYear, sel[0]);
							var onSelect = $.datepicker._get(inst, 'onSelect');
							if (onSelect) {
								var dateStr = $.datepicker._formatDate(inst);

								// trigger custom callback
								onSelect.apply((inst.input ? inst.input[0] : null), [dateStr, inst]);
							}
						else
							$.datepicker._hideDatepicker();
						return false; // don't submit the form
						break; // select the value on enter
				case 27: $.datepicker._hideDatepicker();
						break; // hide on escape
				case 33: $.datepicker._adjustDate(event.target, (event.ctrlKey ?
							-$.datepicker._get(inst, 'stepBigMonths') :
							-$.datepicker._get(inst, 'stepMonths')), 'M');
						break; // previous month/year on page up/+ ctrl
				case 34: $.datepicker._adjustDate(event.target, (event.ctrlKey ?
							+$.datepicker._get(inst, 'stepBigMonths') :
							+$.datepicker._get(inst, 'stepMonths')), 'M');
						break; // next month/year on page down/+ ctrl
				case 35: if (event.ctrlKey || event.metaKey) $.datepicker._clearDate(event.target);
						handled = event.ctrlKey || event.metaKey;
						break; // clear on ctrl or command +end
				case 36: if (event.ctrlKey || event.metaKey) $.datepicker._gotoToday(event.target);
						handled = event.ctrlKey || event.metaKey;
						break; // current on ctrl or command +home
				case 37: if (event.ctrlKey || event.metaKey) $.datepicker._adjustDate(event.target, (isRTL ? +1 : -1), 'D');
						handled = event.ctrlKey || event.metaKey;
						// -1 day on ctrl or command +left
						if (event.originalEvent.altKey) $.datepicker._adjustDate(event.target, (event.ctrlKey ?
									-$.datepicker._get(inst, 'stepBigMonths') :
									-$.datepicker._get(inst, 'stepMonths')), 'M');
						// next month/year on alt +left on Mac
						break;
				case 38: if (event.ctrlKey || event.metaKey) $.datepicker._adjustDate(event.target, -7, 'D');
						handled = event.ctrlKey || event.metaKey;
						break; // -1 week on ctrl or command +up
				case 39: if (event.ctrlKey || event.metaKey) $.datepicker._adjustDate(event.target, (isRTL ? -1 : +1), 'D');
						handled = event.ctrlKey || event.metaKey;
						// +1 day on ctrl or command +right
						if (event.originalEvent.altKey) $.datepicker._adjustDate(event.target, (event.ctrlKey ?
									+$.datepicker._get(inst, 'stepBigMonths') :
									+$.datepicker._get(inst, 'stepMonths')), 'M');
						// next month/year on alt +right
						break;
				case 40: if (event.ctrlKey || event.metaKey) $.datepicker._adjustDate(event.target, +7, 'D');
						handled = event.ctrlKey || event.metaKey;
						break; // +1 week on ctrl or command +down
				default: handled = false;
			}
		else if (event.keyCode == 36 && event.ctrlKey) // display the date picker on ctrl+home
			$.datepicker._showDatepicker(this);
		else {
			handled = false;
		}
		if (handled) {
			event.preventDefault();
			event.stopPropagation();
		}
	},

	/* Filter entered characters - based on date format. */
	_doKeyPress: function(event) {
		var inst = $.datepicker._getInst(event.target);
		if ($.datepicker._get(inst, 'constrainInput')) {
			var chars = $.datepicker._possibleChars($.datepicker._get(inst, 'dateFormat'));
			var chr = String.fromCharCode(event.charCode == undefined ? event.keyCode : event.charCode);
			return event.ctrlKey || event.metaKey || (chr < ' ' || !chars || chars.indexOf(chr) > -1);
		}
	},

	/* Synchronise manual entry and field/alternate field. */
	_doKeyUp: function(event) {
		var inst = $.datepicker._getInst(event.target);
		if (inst.input.val() != inst.lastVal) {
			try {
				var date = $.datepicker.parseDate($.datepicker._get(inst, 'dateFormat'),
					(inst.input ? inst.input.val() : null),
					$.datepicker._getFormatConfig(inst));
				if (date) { // only if valid
					$.datepicker._setDateFromField(inst);
					$.datepicker._updateAlternate(inst);
					$.datepicker._updateDatepicker(inst);
				}
			}
			catch (event) {
				$.datepicker.log(event);
			}
		}
		return true;
	},

	/* Pop-up the date picker for a given input field.
       If false returned from beforeShow event handler do not show. 
	   @param  input  element - the input field attached to the date picker or
	                  event - if triggered by focus */
	_showDatepicker: function(input) {
		input = input.target || input;
		if (input.nodeName.toLowerCase() != 'input') // find from button/image trigger
			input = $('input', input.parentNode)[0];
		if ($.datepicker._isDisabledDatepicker(input) || $.datepicker._lastInput == input) // already here
			return;
		var inst = $.datepicker._getInst(input);
		if ($.datepicker._curInst && $.datepicker._curInst != inst) {
			$.datepicker._curInst.dpDiv.stop(true, true);
			if ( inst && $.datepicker._datepickerShowing ) {
				$.datepicker._hideDatepicker( $.datepicker._curInst.input[0] );
			}
		}
		var beforeShow = $.datepicker._get(inst, 'beforeShow');
		var beforeShowSettings = beforeShow ? beforeShow.apply(input, [input, inst]) : {};
		if(beforeShowSettings === false){
            //false
			return;
		}
		extendRemove(inst.settings, beforeShowSettings);
		inst.lastVal = null;
		$.datepicker._lastInput = input;
		$.datepicker._setDateFromField(inst);
		if ($.datepicker._inDialog) // hide cursor
			input.value = '';
		if (!$.datepicker._pos) { // position below input
			$.datepicker._pos = $.datepicker._findPos(input);
			$.datepicker._pos[1] += input.offsetHeight; // add the height
		}
		var isFixed = false;
		$(input).parents().each(function() {
			isFixed |= $(this).css('position') == 'fixed';
			return !isFixed;
		});
		if (isFixed && $.browser.opera) { // correction for Opera when fixed and scrolled
			$.datepicker._pos[0] -= document.documentElement.scrollLeft;
			$.datepicker._pos[1] -= document.documentElement.scrollTop;
		}
		var offset = {left: $.datepicker._pos[0], top: $.datepicker._pos[1]};
		$.datepicker._pos = null;
		//to avoid flashes on Firefox
		inst.dpDiv.empty();
		// determine sizing offscreen
		inst.dpDiv.css({position: 'absolute', display: 'block', top: '-1000px'});
		$.datepicker._updateDatepicker(inst);
		// fix width for dynamic number of date pickers
		// and adjust position before showing
		offset = $.datepicker._checkOffset(inst, offset, isFixed);
		inst.dpDiv.css({position: ($.datepicker._inDialog && $.blockUI ?
			'static' : (isFixed ? 'fixed' : 'absolute')), display: 'none',
			left: offset.left + 'px', top: offset.top + 'px'});
		if (!inst.inline) {
			var showAnim = $.datepicker._get(inst, 'showAnim');
			var duration = $.datepicker._get(inst, 'duration');
			var postProcess = function() {
				var cover = inst.dpDiv.find('iframe.ui-datepicker-cover'); // IE6- only
				if( !! cover.length ){
					var borders = $.datepicker._getBorders(inst.dpDiv);
					cover.css({left: -borders[0], top: -borders[1],
						width: inst.dpDiv.outerWidth(), height: inst.dpDiv.outerHeight()});
				}
			};
			inst.dpDiv.zIndex($(input).zIndex()+1);
			$.datepicker._datepickerShowing = true;

			// DEPRECATED: after BC for 1.8.x $.effects[ showAnim ] is not needed
			if ( $.effects && ( $.effects.effect[ showAnim ] || $.effects[ showAnim ] ) )
				inst.dpDiv.show(showAnim, $.datepicker._get(inst, 'showOptions'), duration, postProcess);
			else
				inst.dpDiv[showAnim || 'show']((showAnim ? duration : null), postProcess);
			if (!showAnim || !duration)
				postProcess();
			if (inst.input.is(':visible') && !inst.input.is(':disabled'))
				inst.input.focus();
			$.datepicker._curInst = inst;
		}
	},

	/* Generate the date picker content. */
	_updateDatepicker: function(inst) {
		this.maxRows = 4; //Reset the max number of rows being displayed (see #7043)
		var borders = $.datepicker._getBorders(inst.dpDiv);
		instActive = inst; // for delegate hover events
		inst.dpDiv.empty().append(this._generateHTML(inst));
		var cover = inst.dpDiv.find('iframe.ui-datepicker-cover'); // IE6- only
		if( !!cover.length ){ //avoid call to outerXXXX() when not in IE6
			cover.css({left: -borders[0], top: -borders[1], width: inst.dpDiv.outerWidth(), height: inst.dpDiv.outerHeight()})
		}
		inst.dpDiv.find('.' + this._dayOverClass + ' a').mouseover();
		var numMonths = this._getNumberOfMonths(inst);
		var cols = numMonths[1];
		var width = 17;
		inst.dpDiv.removeClass('ui-datepicker-multi-2 ui-datepicker-multi-3 ui-datepicker-multi-4').width('');
		if (cols > 1)
			inst.dpDiv.addClass('ui-datepicker-multi-' + cols).css('width', (width * cols) + 'em');
		inst.dpDiv[(numMonths[0] != 1 || numMonths[1] != 1 ? 'add' : 'remove') +
			'Class']('ui-datepicker-multi');
		inst.dpDiv[(this._get(inst, 'isRTL') ? 'add' : 'remove') +
			'Class']('ui-datepicker-rtl');
		if (inst == $.datepicker._curInst && $.datepicker._datepickerShowing && inst.input &&
				// #6694 - don't focus the input if it's already focused
				// this breaks the change event in IE
				inst.input.is(':visible') && !inst.input.is(':disabled') && inst.input[0] != document.activeElement)
			inst.input.focus();
		// deffered render of the years select (to avoid flashes on Firefox) 
		if( inst.yearshtml ){
			var origyearshtml = inst.yearshtml;
			setTimeout(function(){
				//assure that inst.yearshtml didn't change.
				if( origyearshtml === inst.yearshtml && inst.yearshtml ){
					inst.dpDiv.find('select.ui-datepicker-year:first').replaceWith(inst.yearshtml);
				}
				origyearshtml = inst.yearshtml = null;
			}, 0);
		}
	},

	/* Retrieve the size of left and top borders for an element.
	   @param  elem  (jQuery object) the element of interest
	   @return  (number[2]) the left and top borders */
	_getBorders: function(elem) {
		var convert = function(value) {
			return {thin: 1, medium: 2, thick: 3}[value] || value;
		};
		return [parseFloat(convert(elem.css('border-left-width'))),
			parseFloat(convert(elem.css('border-top-width')))];
	},

	/* Check positioning to remain on screen. */
	_checkOffset: function(inst, offset, isFixed) {
		var dpWidth = inst.dpDiv.outerWidth();
		var dpHeight = inst.dpDiv.outerHeight();
		var inputWidth = inst.input ? inst.input.outerWidth() : 0;
		var inputHeight = inst.input ? inst.input.outerHeight() : 0;
		var viewWidth = document.documentElement.clientWidth + $(document).scrollLeft();
		var viewHeight = document.documentElement.clientHeight + $(document).scrollTop();

		offset.left -= (this._get(inst, 'isRTL') ? (dpWidth - inputWidth) : 0);
		offset.left -= (isFixed && offset.left == inst.input.offset().left) ? $(document).scrollLeft() : 0;
		offset.top -= (isFixed && offset.top == (inst.input.offset().top + inputHeight)) ? $(document).scrollTop() : 0;

		// now check if datepicker is showing outside window viewport - move to a better place if so.
		offset.left -= Math.min(offset.left, (offset.left + dpWidth > viewWidth && viewWidth > dpWidth) ?
			Math.abs(offset.left + dpWidth - viewWidth) : 0);
		offset.top -= Math.min(offset.top, (offset.top + dpHeight > viewHeight && viewHeight > dpHeight) ?
			Math.abs(dpHeight + inputHeight) : 0);

		return offset;
	},

	/* Find an object's position on the screen. */
	_findPos: function(obj) {
		var inst = this._getInst(obj);
		var isRTL = this._get(inst, 'isRTL');
        while (obj && (obj.type == 'hidden' || obj.nodeType != 1 || $.expr.filters.hidden(obj))) {
            obj = obj[isRTL ? 'previousSibling' : 'nextSibling'];
        }
        var position = $(obj).offset();
	    return [position.left, position.top];
	},

	/* Hide the date picker from view.
	   @param  input  element - the input field attached to the date picker */
	_hideDatepicker: function(input) {
		var inst = this._curInst;
		if (!inst || (input && inst != $.data(input, PROP_NAME)))
			return;
		if (this._datepickerShowing) {
			var showAnim = this._get(inst, 'showAnim');
			var duration = this._get(inst, 'duration');
			var that = this;
			var postProcess = function() {
				$.datepicker._tidyDialog(inst);
				that._curInst = null;
			};

			// DEPRECATED: after BC for 1.8.x $.effects[ showAnim ] is not needed
			if ( $.effects && ( $.effects.effect[ showAnim ] || $.effects[ showAnim ] ) )
				inst.dpDiv.hide(showAnim, $.datepicker._get(inst, 'showOptions'), duration, postProcess);
			else
				inst.dpDiv[(showAnim == 'slideDown' ? 'slideUp' :
					(showAnim == 'fadeIn' ? 'fadeOut' : 'hide'))]((showAnim ? duration : null), postProcess);
			if (!showAnim)
				postProcess();
			this._datepickerShowing = false;
			var onClose = this._get(inst, 'onClose');
			if (onClose)
				onClose.apply((inst.input ? inst.input[0] : null),
					[(inst.input ? inst.input.val() : ''), inst]);
			this._lastInput = null;
			if (this._inDialog) {
				this._dialogInput.css({ position: 'absolute', left: '0', top: '-100px' });
				if ($.blockUI) {
					$.unblockUI();
					$('body').append(this.dpDiv);
				}
			}
			this._inDialog = false;
		}
	},

	/* Tidy up after a dialog display. */
	_tidyDialog: function(inst) {
		inst.dpDiv.removeClass(this._dialogClass).unbind('.ui-datepicker-calendar');
	},

	/* Close date picker if clicked elsewhere. */
	_checkExternalClick: function(event) {
		if (!$.datepicker._curInst)
			return;

		var $target = $(event.target),
			inst = $.datepicker._getInst($target[0]);

		if ( ( ( $target[0].id != $.datepicker._mainDivId &&
				$target.parents('#' + $.datepicker._mainDivId).length == 0 &&
				!$target.hasClass($.datepicker.markerClassName) &&
				!$target.closest("." + $.datepicker._triggerClass).length &&
				$.datepicker._datepickerShowing && !($.datepicker._inDialog && $.blockUI) ) ) ||
			( $target.hasClass($.datepicker.markerClassName) && $.datepicker._curInst != inst ) )
			$.datepicker._hideDatepicker();
	},

	/* Adjust one of the date sub-fields. */
	_adjustDate: function(id, offset, period) {
		var target = $(id);
		var inst = this._getInst(target[0]);
		if (this._isDisabledDatepicker(target[0])) {
			return;
		}
		this._adjustInstDate(inst, offset +
			(period == 'M' ? this._get(inst, 'showCurrentAtPos') : 0), // undo positioning
			period);
		this._updateDatepicker(inst);
	},

	/* Action for current link. */
	_gotoToday: function(id) {
		var target = $(id);
		var inst = this._getInst(target[0]);
		if (this._get(inst, 'gotoCurrent') && inst.currentDay) {
			inst.selectedDay = inst.currentDay;
			inst.drawMonth = inst.selectedMonth = inst.currentMonth;
			inst.drawYear = inst.selectedYear = inst.currentYear;
		}
		else {
			var date = new Date();
			inst.selectedDay = date.getDate();
			inst.drawMonth = inst.selectedMonth = date.getMonth();
			inst.drawYear = inst.selectedYear = date.getFullYear();
		}
		this._notifyChange(inst);
		this._adjustDate(target);
	},

	/* Action for selecting a new month/year. */
	_selectMonthYear: function(id, select, period) {
		var target = $(id);
		var inst = this._getInst(target[0]);
		inst['selected' + (period == 'M' ? 'Month' : 'Year')] =
		inst['draw' + (period == 'M' ? 'Month' : 'Year')] =
			parseInt(select.options[select.selectedIndex].value,10);
		this._notifyChange(inst);
		this._adjustDate(target);
	},

	/* Action for selecting a day. */
	_selectDay: function(id, month, year, td) {
		var target = $(id);
		if ($(td).hasClass(this._unselectableClass) || this._isDisabledDatepicker(target[0])) {
			return;
		}
		var inst = this._getInst(target[0]);
		inst.selectedDay = inst.currentDay = $('a', td).html();
		inst.selectedMonth = inst.currentMonth = month;
		inst.selectedYear = inst.currentYear = year;
		this._selectDate(id, this._formatDate(inst,
			inst.currentDay, inst.currentMonth, inst.currentYear));
	},

	/* Erase the input field and hide the date picker. */
	_clearDate: function(id) {
		var target = $(id);
		var inst = this._getInst(target[0]);
		this._selectDate(target, '');
	},

	/* Update the input field with the selected date. */
	_selectDate: function(id, dateStr) {
		var target = $(id);
		var inst = this._getInst(target[0]);
		dateStr = (dateStr != null ? dateStr : this._formatDate(inst));
		if (inst.input)
			inst.input.val(dateStr);
		this._updateAlternate(inst);
		var onSelect = this._get(inst, 'onSelect');
		if (onSelect)
			onSelect.apply((inst.input ? inst.input[0] : null), [dateStr, inst]);  // trigger custom callback
		else if (inst.input)
			inst.input.trigger('change'); // fire the change event
		if (inst.inline)
			this._updateDatepicker(inst);
		else {
			this._hideDatepicker();
			this._lastInput = inst.input[0];
			if (typeof(inst.input[0]) != 'object')
				inst.input.focus(); // restore focus
			this._lastInput = null;
		}
	},

	/* Update any alternate field to synchronise with the main field. */
	_updateAlternate: function(inst) {
		var altField = this._get(inst, 'altField');
		if (altField) { // update alternate field too
			var altFormat = this._get(inst, 'altFormat') || this._get(inst, 'dateFormat');
			var date = this._getDate(inst);
			var dateStr = this.formatDate(altFormat, date, this._getFormatConfig(inst));
			$(altField).each(function() { $(this).val(dateStr); });
		}
	},

	/* Set as beforeShowDay function to prevent selection of weekends.
	   @param  date  Date - the date to customise
	   @return [boolean, string] - is this date selectable?, what is its CSS class? */
	noWeekends: function(date) {
		var day = date.getDay();
		return [(day > 0 && day < 6), ''];
	},

	/* Set as calculateWeek to determine the week of the year based on the ISO 8601 definition.
	   @param  date  Date - the date to get the week for
	   @return  number - the number of the week within the year that contains this date */
	iso8601Week: function(date) {
		var checkDate = new Date(date.getTime());
		// Find Thursday of this week starting on Monday
		checkDate.setDate(checkDate.getDate() + 4 - (checkDate.getDay() || 7));
		var time = checkDate.getTime();
		checkDate.setMonth(0); // Compare with Jan 1
		checkDate.setDate(1);
		return Math.floor(Math.round((time - checkDate) / 86400000) / 7) + 1;
	},

	/* Parse a string value into a date object.
	   See formatDate below for the possible formats.

	   @param  format    string - the expected format of the date
	   @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[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 extracted date value or null if value is blank */
	parseDate: function (format, value, settings) {
		if (format == null || value == null)
			throw 'Invalid arguments';
		value = (typeof value == 'object' ? value.toString() : value + '');
		if (value == '')
			return null;
		var shortYearCutoff = (settings ? settings.shortYearCutoff : null) || this._defaults.shortYearCutoff;
		shortYearCutoff = (typeof shortYearCutoff != 'string' ? shortYearCutoff :
				new Date().getFullYear() % 100 + parseInt(shortYearCutoff, 10));
		var dayNamesShort = (settings ? settings.dayNamesShort : null) || this._defaults.dayNamesShort;
		var dayNames = (settings ? settings.dayNames : null) || this._defaults.dayNames;
		var monthNamesShort = (settings ? settings.monthNamesShort : null) || this._defaults.monthNamesShort;
		var monthNames = (settings ? settings.monthNames : null) || this._defaults.monthNames;
		var year = -1;
		var month = -1;
		var day = -1;
		var doy = -1;
		var literal = false;
		// Check whether a format character is doubled
		var lookAhead = function(match) {
			var matches = (iFormat + 1 < format.length && format.charAt(iFormat + 1) == match);
			if (matches)
				iFormat++;
			return matches;
		};
		// Extract a number from the string value
		var getNumber = function(match) {
			var isDoubled = lookAhead(match);
			var size = (match == '@' ? 14 : (match == '!' ? 20 :
				(match == 'y' && isDoubled ? 4 : (match == 'o' ? 3 : 2))));
			var digits = new RegExp('^\\d{1,' + size + '}');
			var num = value.substring(iValue).match(digits);
			if (!num)
				throw 'Missing number at position ' + 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) {
			var names = $.map(lookAhead(match) ? longNames : shortNames, function (v, k) {
				return [ [k, v] ];
			}).sort(function (a, b) {
				return -(a[1].length - b[1].length);
			});
			var index = -1;
			$.each(names, function (i, pair) {
				var name = pair[1];
				if (value.substr(iValue, name.length).toLowerCase() == name.toLowerCase()) {
					index = pair[0];
					iValue += name.length;
					return false;
				}
			});
			if (index != -1)
				return index + 1;
			else
				throw 'Unknown name at position ' + 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 ' + iValue;
			iValue++;
		};
		var iValue = 0;
		for (var iFormat = 0; iFormat < format.length; iFormat++) {
			if (literal)
				if (format.charAt(iFormat) == "'" && !lookAhead("'"))
					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 'm':
						month = getNumber('m');
						break;
					case 'M':
						month = getName('M', monthNamesShort, monthNames);
						break;
					case 'y':
						year = getNumber('y');
						break;
					case '@':
						var date = new Date(getNumber('@'));
						year = date.getFullYear();
						month = date.getMonth() + 1;
						day = date.getDate();
						break;
					case '!':
						var date = new Date((getNumber('!') - this._ticksTo1970) / 10000);
						year = date.getFullYear();
						month = date.getMonth() + 1;
						day = date.getDate();
						break;
					case "'":
						if (lookAhead("'"))
							checkLiteral();
						else
							literal = true;
						break;
					default:
						checkLiteral();
				}
		}
		if (iValue < value.length){
			var extra = value.substr(iValue);
			if (!/^\s+/.test(extra)) {
				throw "Extra/unparsed characters found in date: " + extra;
			}
		}
		if (year == -1)
			year = new Date().getFullYear();
		else if (year < 100)
			year += new Date().getFullYear() - new Date().getFullYear() % 100 +
				(year <= shortYearCutoff ? 0 : -100);
		if (doy > -1) {
			month = 1;
			day = doy;
			do {
				var dim = this._getDaysInMonth(year, month - 1);
				if (day <= dim)
					break;
				month++;
				day -= dim;
			} while (true);
		}
		var date = this._daylightSavingAdjust(new Date(year, month - 1, day));
		if (date.getFullYear() != year || date.getMonth() + 1 != month || date.getDate() != day)
			throw 'Invalid date'; // E.g. 31/02/00
		return date;
	},

	/* Standard date formats. */
	ATOM: 'yy-mm-dd', // RFC 3339 (ISO 8601)
	COOKIE: 'D, dd M yy',
	ISO_8601: 'yy-mm-dd',
	RFC_822: 'D, d M y',
	RFC_850: 'DD, dd-M-y',
	RFC_1036: 'D, d M y',
	RFC_1123: 'D, d M yy',
	RFC_2822: 'D, d M yy',
	RSS: 'D, d M y', // RFC 822
	TICKS: '!',
	TIMESTAMP: '@',
	W3C: 'yy-mm-dd', // ISO 8601

	_ticksTo1970: (((1970 - 1) * 365 + Math.floor(1970 / 4) - Math.floor(1970 / 100) +
		Math.floor(1970 / 400)) * 24 * 60 * 60 * 10000000),

	/* 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
	   m  - month of year (no leading zero)
	   mm - month of year (two digit)
	   M  - month name short
	   MM - month name long
	   y  - year (two digit)
	   yy - year (four digit)
	   @ - Unix timestamp (ms since 01/01/1970)
	   ! - Windows ticks (100ns since 01/01/0001)
	   '...' - literal text
	   '' - single quote

	   @param  format    string - the desired format of the date
	   @param  date      Date - the date value to format
	   @param  settings  Object - attributes include:
	                     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  string - the date in the above format */
	formatDate: function (format, date, settings) {
		if (!date)
			return '';
		var dayNamesShort = (settings ? settings.dayNamesShort : null) || this._defaults.dayNamesShort;
		var dayNames = (settings ? settings.dayNames : null) || this._defaults.dayNames;
		var monthNamesShort = (settings ? settings.monthNamesShort : null) || this._defaults.monthNamesShort;
		var monthNames = (settings ? settings.monthNames : null) || this._defaults.monthNames;
		// Check whether a format character is doubled
		var lookAhead = function(match) {
			var matches = (iFormat + 1 < format.length && format.charAt(iFormat + 1) == match);
			if (matches)
				iFormat++;
			return matches;
		};
		// Format a number, with leading zero if necessary
		var formatNumber = function(match, value, len) {
			var num = '' + value;
			if (lookAhead(match))
				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 (lookAhead(match) ? longNames[value] : shortNames[value]);
		};
		var output = '';
		var literal = false;
		if (date)
			for (var iFormat = 0; iFormat < format.length; iFormat++) {
				if (literal)
					if (format.charAt(iFormat) == "'" && !lookAhead("'"))
						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',
								Math.round((new Date(date.getFullYear(), date.getMonth(), date.getDate()).getTime() - new Date(date.getFullYear(), 0, 0).getTime()) / 86400000), 3);
							break;
						case 'm':
							output += formatNumber('m', date.getMonth() + 1, 2);
							break;
						case 'M':
							output += formatName('M', date.getMonth(), monthNamesShort, monthNames);
							break;
						case 'y':
							output += (lookAhead('y') ? date.getFullYear() :
								(date.getYear() % 100 < 10 ? '0' : '') + date.getYear() % 100);
							break;
						case '@':
							output += date.getTime();
							break;
						case '!':
							output += date.getTime() * 10000 + this._ticksTo1970;
							break;
						case "'":
							if (lookAhead("'"))
								output += "'";
							else
								literal = true;
							break;
						default:
							output += format.charAt(iFormat);
					}
			}
		return output;
	},

	/* Extract all possible characters from the date format. */
	_possibleChars: function (format) {
		var chars = '';
		var literal = false;
		// Check whether a format character is doubled
		var lookAhead = function(match) {
			var matches = (iFormat + 1 < format.length && format.charAt(iFormat + 1) == match);
			if (matches)
				iFormat++;
			return matches;
		};
		for (var iFormat = 0; iFormat < format.length; iFormat++)
			if (literal)
				if (format.charAt(iFormat) == "'" && !lookAhead("'"))
					literal = false;
				else
					chars += format.charAt(iFormat);
			else
				switch (format.charAt(iFormat)) {
					case 'd': case 'm': case 'y': case '@':
						chars += '0123456789';
						break;
					case 'D': case 'M':
						return null; // Accept anything
					case "'":
						if (lookAhead("'"))
							chars += "'";
						else
							literal = true;
						break;
					default:
						chars += format.charAt(iFormat);
				}
		return chars;
	},

	/* Get a setting value, defaulting if necessary. */
	_get: function(inst, name) {
		return inst.settings[name] !== undefined ?
			inst.settings[name] : this._defaults[name];
	},

	/* Parse existing date and initialise date picker. */
	_setDateFromField: function(inst, noDefault) {
		if (inst.input.val() == inst.lastVal) {
			return;
		}
		var dateFormat = this._get(inst, 'dateFormat');
		var dates = inst.lastVal = inst.input ? inst.input.val() : null;
		var date, defaultDate;
		date = defaultDate = this._getDefaultDate(inst);
		var settings = this._getFormatConfig(inst);
		try {
			date = this.parseDate(dateFormat, dates, settings) || defaultDate;
		} catch (event) {
			this.log(event);
			dates = (noDefault ? '' : dates);
		}
		inst.selectedDay = date.getDate();
		inst.drawMonth = inst.selectedMonth = date.getMonth();
		inst.drawYear = inst.selectedYear = date.getFullYear();
		inst.currentDay = (dates ? date.getDate() : 0);
		inst.currentMonth = (dates ? date.getMonth() : 0);
		inst.currentYear = (dates ? date.getFullYear() : 0);
		this._adjustInstDate(inst);
	},

	/* Retrieve the default date shown on opening. */
	_getDefaultDate: function(inst) {
		return this._restrictMinMax(inst,
			this._determineDate(inst, this._get(inst, 'defaultDate'), new Date()));
	},

	/* A date may be specified as an exact value or a relative one. */
	_determineDate: function(inst, date, defaultDate) {
		var offsetNumeric = function(offset) {
			var date = new Date();
			date.setDate(date.getDate() + offset);
			return date;
		};
		var offsetString = function(offset) {
			try {
				return $.datepicker.parseDate($.datepicker._get(inst, 'dateFormat'),
					offset, $.datepicker._getFormatConfig(inst));
			}
			catch (e) {
				// Ignore
			}
			var date = (offset.toLowerCase().match(/^c/) ?
				$.datepicker._getDate(inst) : null) || new Date();
			var year = date.getFullYear();
			var month = date.getMonth();
			var day = date.getDate();
			var pattern = /([+-]?[0-9]+)\s*(d|D|w|W|m|M|y|Y)?/g;
			var matches = pattern.exec(offset);
			while (matches) {
				switch (matches[2] || 'd') {
					case 'd' : case 'D' :
						day += parseInt(matches[1],10); break;
					case 'w' : case 'W' :
						day += parseInt(matches[1],10) * 7; break;
					case 'm' : case 'M' :
						month += parseInt(matches[1],10);
						day = Math.min(day, $.datepicker._getDaysInMonth(year, month));
						break;
					case 'y': case 'Y' :
						year += parseInt(matches[1],10);
						day = Math.min(day, $.datepicker._getDaysInMonth(year, month));
						break;
				}
				matches = pattern.exec(offset);
			}
			return new Date(year, month, day);
		};
		var newDate = (date == null || date === '' ? defaultDate : (typeof date == 'string' ? offsetString(date) :
			(typeof date == 'number' ? (isNaN(date) ? defaultDate : offsetNumeric(date)) : new Date(date.getTime()))));
		newDate = (newDate && newDate.toString() == 'Invalid Date' ? defaultDate : newDate);
		if (newDate) {
			newDate.setHours(0);
			newDate.setMinutes(0);
			newDate.setSeconds(0);
			newDate.setMilliseconds(0);
		}
		return this._daylightSavingAdjust(newDate);
	},

	/* Handle switch to/from daylight saving.
	   Hours may be non-zero on daylight saving cut-over:
	   > 12 when midnight changeover, but then cannot generate
	   midnight datetime, so jump to 1AM, otherwise reset.
	   @param  date  (Date) the date to check
	   @return  (Date) the corrected date */
	_daylightSavingAdjust: function(date) {
		if (!date) return null;
		date.setHours(date.getHours() > 12 ? date.getHours() + 2 : 0);
		return date;
	},

	/* Set the date(s) directly. */
	_setDate: function(inst, date, noChange) {
		var clear = !date;
		var origMonth = inst.selectedMonth;
		var origYear = inst.selectedYear;
		var newDate = this._restrictMinMax(inst, this._determineDate(inst, date, new Date()));
		inst.selectedDay = inst.currentDay = newDate.getDate();
		inst.drawMonth = inst.selectedMonth = inst.currentMonth = newDate.getMonth();
		inst.drawYear = inst.selectedYear = inst.currentYear = newDate.getFullYear();
		if ((origMonth != inst.selectedMonth || origYear != inst.selectedYear) && !noChange)
			this._notifyChange(inst);
		this._adjustInstDate(inst);
		if (inst.input) {
			inst.input.val(clear ? '' : this._formatDate(inst));
		}
	},

	/* Retrieve the date(s) directly. */
	_getDate: function(inst) {
		var startDate = (!inst.currentYear || (inst.input && inst.input.val() == '') ? null :
			this._daylightSavingAdjust(new Date(
			inst.currentYear, inst.currentMonth, inst.currentDay)));
			return startDate;
	},

	/* Generate the HTML for the current state of the date picker. */
	_generateHTML: function(inst) {
		var today = new Date();
		today = this._daylightSavingAdjust(
			new Date(today.getFullYear(), today.getMonth(), today.getDate())); // clear time
		var isRTL = this._get(inst, 'isRTL');
		var showButtonPanel = this._get(inst, 'showButtonPanel');
		var hideIfNoPrevNext = this._get(inst, 'hideIfNoPrevNext');
		var navigationAsDateFormat = this._get(inst, 'navigationAsDateFormat');
		var numMonths = this._getNumberOfMonths(inst);
		var showCurrentAtPos = this._get(inst, 'showCurrentAtPos');
		var stepMonths = this._get(inst, 'stepMonths');
		var isMultiMonth = (numMonths[0] != 1 || numMonths[1] != 1);
		var currentDate = this._daylightSavingAdjust((!inst.currentDay ? new Date(9999, 9, 9) :
			new Date(inst.currentYear, inst.currentMonth, inst.currentDay)));
		var minDate = this._getMinMaxDate(inst, 'min');
		var maxDate = this._getMinMaxDate(inst, 'max');
		var drawMonth = inst.drawMonth - showCurrentAtPos;
		var drawYear = inst.drawYear;
		if (drawMonth < 0) {
			drawMonth += 12;
			drawYear--;
		}
		if (maxDate) {
			var maxDraw = this._daylightSavingAdjust(new Date(maxDate.getFullYear(),
				maxDate.getMonth() - (numMonths[0] * numMonths[1]) + 1, maxDate.getDate()));
			maxDraw = (minDate && maxDraw < minDate ? minDate : maxDraw);
			while (this._daylightSavingAdjust(new Date(drawYear, drawMonth, 1)) > maxDraw) {
				drawMonth--;
				if (drawMonth < 0) {
					drawMonth = 11;
					drawYear--;
				}
			}
		}
		inst.drawMonth = drawMonth;
		inst.drawYear = drawYear;
		var prevText = this._get(inst, 'prevText');
		prevText = (!navigationAsDateFormat ? prevText : this.formatDate(prevText,
			this._daylightSavingAdjust(new Date(drawYear, drawMonth - stepMonths, 1)),
			this._getFormatConfig(inst)));
		var prev = (this._canAdjustMonth(inst, -1, drawYear, drawMonth) ?
			'<a class="ui-datepicker-prev ui-corner-all" onclick="DP_jQuery_' + dpuuid +
			'.datepicker._adjustDate(\'#' + inst.id + '\', -' + stepMonths + ', \'M\');"' +
			' title="' + prevText + '"><span class="ui-icon ui-icon-circle-triangle-' + ( isRTL ? 'e' : 'w') + '">' + prevText + '</span></a>' :
			(hideIfNoPrevNext ? '' : '<a class="ui-datepicker-prev ui-corner-all ui-state-disabled" title="'+ prevText +'"><span class="ui-icon ui-icon-circle-triangle-' + ( isRTL ? 'e' : 'w') + '">' + prevText + '</span></a>'));
		var nextText = this._get(inst, 'nextText');
		nextText = (!navigationAsDateFormat ? nextText : this.formatDate(nextText,
			this._daylightSavingAdjust(new Date(drawYear, drawMonth + stepMonths, 1)),
			this._getFormatConfig(inst)));
		var next = (this._canAdjustMonth(inst, +1, drawYear, drawMonth) ?
			'<a class="ui-datepicker-next ui-corner-all" onclick="DP_jQuery_' + dpuuid +
			'.datepicker._adjustDate(\'#' + inst.id + '\', +' + stepMonths + ', \'M\');"' +
			' title="' + nextText + '"><span class="ui-icon ui-icon-circle-triangle-' + ( isRTL ? 'w' : 'e') + '">' + nextText + '</span></a>' :
			(hideIfNoPrevNext ? '' : '<a class="ui-datepicker-next ui-corner-all ui-state-disabled" title="'+ nextText + '"><span class="ui-icon ui-icon-circle-triangle-' + ( isRTL ? 'w' : 'e') + '">' + nextText + '</span></a>'));
		var currentText = this._get(inst, 'currentText');
		var gotoDate = (this._get(inst, 'gotoCurrent') && inst.currentDay ? currentDate : today);
		currentText = (!navigationAsDateFormat ? currentText :
			this.formatDate(currentText, gotoDate, this._getFormatConfig(inst)));
		var controls = (!inst.inline ? '<button type="button" class="ui-datepicker-close ui-state-default ui-priority-primary ui-corner-all" onclick="DP_jQuery_' + dpuuid +
			'.datepicker._hideDatepicker();">' + this._get(inst, 'closeText') + '</button>' : '');
		var buttonPanel = (showButtonPanel) ? '<div class="ui-datepicker-buttonpane ui-widget-content">' + (isRTL ? controls : '') +
			(this._isInRange(inst, gotoDate) ? '<button type="button" class="ui-datepicker-current ui-state-default ui-priority-secondary ui-corner-all" onclick="DP_jQuery_' + dpuuid +
			'.datepicker._gotoToday(\'#' + inst.id + '\');"' +
			'>' + currentText + '</button>' : '') + (isRTL ? '' : controls) + '</div>' : '';
		var firstDay = parseInt(this._get(inst, 'firstDay'),10);
		firstDay = (isNaN(firstDay) ? 0 : firstDay);
		var showWeek = this._get(inst, 'showWeek');
		var dayNames = this._get(inst, 'dayNames');
		var dayNamesShort = this._get(inst, 'dayNamesShort');
		var dayNamesMin = this._get(inst, 'dayNamesMin');
		var monthNames = this._get(inst, 'monthNames');
		var monthNamesShort = this._get(inst, 'monthNamesShort');
		var beforeShowDay = this._get(inst, 'beforeShowDay');
		var showOtherMonths = this._get(inst, 'showOtherMonths');
		var selectOtherMonths = this._get(inst, 'selectOtherMonths');
		var calculateWeek = this._get(inst, 'calculateWeek') || this.iso8601Week;
		var defaultDate = this._getDefaultDate(inst);
		var html = '';
		for (var row = 0; row < numMonths[0]; row++) {
			var group = '';
			this.maxRows = 4;
			for (var col = 0; col < numMonths[1]; col++) {
				var selectedDate = this._daylightSavingAdjust(new Date(drawYear, drawMonth, inst.selectedDay));
				var cornerClass = ' ui-corner-all';
				var calender = '';
				if (isMultiMonth) {
					calender += '<div class="ui-datepicker-group';
					if (numMonths[1] > 1)
						switch (col) {
							case 0: calender += ' ui-datepicker-group-first';
								cornerClass = ' ui-corner-' + (isRTL ? 'right' : 'left'); break;
							case numMonths[1]-1: calender += ' ui-datepicker-group-last';
								cornerClass = ' ui-corner-' + (isRTL ? 'left' : 'right'); break;
							default: calender += ' ui-datepicker-group-middle'; cornerClass = ''; break;
						}
					calender += '">';
				}
				calender += '<div class="ui-datepicker-header ui-widget-header ui-helper-clearfix' + cornerClass + '">' +
					(/all|left/.test(cornerClass) && row == 0 ? (isRTL ? next : prev) : '') +
					(/all|right/.test(cornerClass) && row == 0 ? (isRTL ? prev : next) : '') +
					this._generateMonthYearHeader(inst, drawMonth, drawYear, minDate, maxDate,
					row > 0 || col > 0, monthNames, monthNamesShort) + // draw month headers
					'</div><table class="ui-datepicker-calendar"><thead>' +
					'<tr>';
				var thead = (showWeek ? '<th class="ui-datepicker-week-col">' + this._get(inst, 'weekHeader') + '</th>' : '');
				for (var dow = 0; dow < 7; dow++) { // days of the week
					var day = (dow + firstDay) % 7;
					thead += '<th' + ((dow + firstDay + 6) % 7 >= 5 ? ' class="ui-datepicker-week-end"' : '') + '>' +
						'<span title="' + dayNames[day] + '">' + dayNamesMin[day] + '</span></th>';
				}
				calender += thead + '</tr></thead><tbody>';
				var daysInMonth = this._getDaysInMonth(drawYear, drawMonth);
				if (drawYear == inst.selectedYear && drawMonth == inst.selectedMonth)
					inst.selectedDay = Math.min(inst.selectedDay, daysInMonth);
				var leadDays = (this._getFirstDayOfMonth(drawYear, drawMonth) - firstDay + 7) % 7;
				var curRows = Math.ceil((leadDays + daysInMonth) / 7); // calculate the number of rows to generate
				var numRows = (isMultiMonth ? this.maxRows > curRows ? this.maxRows : curRows : curRows); //If multiple months, use the higher number of rows (see #7043)
				this.maxRows = numRows;
				var printDate = this._daylightSavingAdjust(new Date(drawYear, drawMonth, 1 - leadDays));
				for (var dRow = 0; dRow < numRows; dRow++) { // create date picker rows
					calender += '<tr>';
					var tbody = (!showWeek ? '' : '<td class="ui-datepicker-week-col">' +
						this._get(inst, 'calculateWeek')(printDate) + '</td>');
					for (var dow = 0; dow < 7; dow++) { // create date picker days
						var daySettings = (beforeShowDay ?
							beforeShowDay.apply((inst.input ? inst.input[0] : null), [printDate]) : [true, '']);
						var otherMonth = (printDate.getMonth() != drawMonth);
						var unselectable = (otherMonth && !selectOtherMonths) || !daySettings[0] ||
							(minDate && printDate < minDate) || (maxDate && printDate > maxDate);
						tbody += '<td class="' +
							((dow + firstDay + 6) % 7 >= 5 ? ' ui-datepicker-week-end' : '') + // highlight weekends
							(otherMonth ? ' ui-datepicker-other-month' : '') + // highlight days from other months
							((printDate.getTime() == selectedDate.getTime() && drawMonth == inst.selectedMonth && inst._keyEvent) || // user pressed key
							(defaultDate.getTime() == printDate.getTime() && defaultDate.getTime() == selectedDate.getTime()) ?
							// or defaultDate is current printedDate and defaultDate is selectedDate
							' ' + this._dayOverClass : '') + // highlight selected day
							(unselectable ? ' ' + this._unselectableClass + ' ui-state-disabled': '') +  // highlight unselectable days
							(otherMonth && !showOtherMonths ? '' : ' ' + daySettings[1] + // highlight custom dates
							(printDate.getTime() == currentDate.getTime() ? ' ' + this._currentClass : '') + // highlight selected day
							(printDate.getTime() == today.getTime() ? ' ui-datepicker-today' : '')) + '"' + // highlight today (if different)
							((!otherMonth || showOtherMonths) && daySettings[2] ? ' title="' + daySettings[2] + '"' : '') + // cell title
							(unselectable ? '' : ' onclick="DP_jQuery_' + dpuuid + '.datepicker._selectDay(\'#' +
							inst.id + '\',' + printDate.getMonth() + ',' + printDate.getFullYear() + ', this);return false;"') + '>' + // actions
							(otherMonth && !showOtherMonths ? '&#xa0;' : // display for other months
							(unselectable ? '<span class="ui-state-default">' + printDate.getDate() + '</span>' : '<a class="ui-state-default' +
							(printDate.getTime() == today.getTime() ? ' ui-state-highlight' : '') +
							(printDate.getTime() == currentDate.getTime() ? ' ui-state-active' : '') + // highlight selected day
							(otherMonth ? ' ui-priority-secondary' : '') + // distinguish dates from other months
							'" href="#">' + printDate.getDate() + '</a>')) + '</td>'; // display selectable date
						printDate.setDate(printDate.getDate() + 1);
						printDate = this._daylightSavingAdjust(printDate);
					}
					calender += tbody + '</tr>';
				}
				drawMonth++;
				if (drawMonth > 11) {
					drawMonth = 0;
					drawYear++;
				}
				calender += '</tbody></table>' + (isMultiMonth ? '</div>' + 
							((numMonths[0] > 0 && col == numMonths[1]-1) ? '<div class="ui-datepicker-row-break"></div>' : '') : '');
				group += calender;
			}
			html += group;
		}
		html += buttonPanel + ($.browser.msie && parseInt($.browser.version,10) < 7 && !inst.inline ?
			'<iframe src="javascript:false;" class="ui-datepicker-cover" frameborder="0"></iframe>' : '');
		inst._keyEvent = false;
		return html;
	},

	/* Generate the month and year header. */
	_generateMonthYearHeader: function(inst, drawMonth, drawYear, minDate, maxDate,
			secondary, monthNames, monthNamesShort) {
		var changeMonth = this._get(inst, 'changeMonth');
		var changeYear = this._get(inst, 'changeYear');
		var showMonthAfterYear = this._get(inst, 'showMonthAfterYear');
		var html = '<div class="ui-datepicker-title">';
		var monthHtml = '';
		// month selection
		if (secondary || !changeMonth)
			monthHtml += '<span class="ui-datepicker-month">' + monthNames[drawMonth] + '</span>';
		else {
			var inMinYear = (minDate && minDate.getFullYear() == drawYear);
			var inMaxYear = (maxDate && maxDate.getFullYear() == drawYear);
			monthHtml += '<select class="ui-datepicker-month" ' +
				'onchange="DP_jQuery_' + dpuuid + '.datepicker._selectMonthYear(\'#' + inst.id + '\', this, \'M\');" ' +
			 	'>';
			for (var month = 0; month < 12; month++) {
				if ((!inMinYear || month >= minDate.getMonth()) &&
						(!inMaxYear || month <= maxDate.getMonth()))
					monthHtml += '<option value="' + month + '"' +
						(month == drawMonth ? ' selected="selected"' : '') +
						'>' + monthNamesShort[month] + '</option>';
			}
			monthHtml += '</select>';
		}
		if (!showMonthAfterYear)
			html += monthHtml + (secondary || !(changeMonth && changeYear) ? '&#xa0;' : '');
		// year selection
		if ( !inst.yearshtml ) {
			inst.yearshtml = '';
			if (secondary || !changeYear)
				html += '<span class="ui-datepicker-year">' + drawYear + '</span>';
			else {
				// determine range of years to display
				var years = this._get(inst, 'yearRange').split(':');
				var thisYear = new Date().getFullYear();
				var determineYear = function(value) {
					var year = (value.match(/c[+-].*/) ? drawYear + parseInt(value.substring(1), 10) :
						(value.match(/[+-].*/) ? thisYear + parseInt(value, 10) :
						parseInt(value, 10)));
					return (isNaN(year) ? thisYear : year);
				};
				var year = determineYear(years[0]);
				var endYear = Math.max(year, determineYear(years[1] || ''));
				year = (minDate ? Math.max(year, minDate.getFullYear()) : year);
				endYear = (maxDate ? Math.min(endYear, maxDate.getFullYear()) : endYear);
				inst.yearshtml += '<select class="ui-datepicker-year" ' +
					'onchange="DP_jQuery_' + dpuuid + '.datepicker._selectMonthYear(\'#' + inst.id + '\', this, \'Y\');" ' +
					'>';
				for (; year <= endYear; year++) {
					inst.yearshtml += '<option value="' + year + '"' +
						(year == drawYear ? ' selected="selected"' : '') +
						'>' + year + '</option>';
				}
				inst.yearshtml += '</select>';
				
				html += inst.yearshtml;
				inst.yearshtml = null;
			}
		}
		html += this._get(inst, 'yearSuffix');
		if (showMonthAfterYear)
			html += (secondary || !(changeMonth && changeYear) ? '&#xa0;' : '') + monthHtml;
		html += '</div>'; // Close datepicker_header
		return html;
	},

	/* Adjust one of the date sub-fields. */
	_adjustInstDate: function(inst, offset, period) {
		var year = inst.drawYear + (period == 'Y' ? offset : 0);
		var month = inst.drawMonth + (period == 'M' ? offset : 0);
		var day = Math.min(inst.selectedDay, this._getDaysInMonth(year, month)) +
			(period == 'D' ? offset : 0);
		var date = this._restrictMinMax(inst,
			this._daylightSavingAdjust(new Date(year, month, day)));
		inst.selectedDay = date.getDate();
		inst.drawMonth = inst.selectedMonth = date.getMonth();
		inst.drawYear = inst.selectedYear = date.getFullYear();
		if (period == 'M' || period == 'Y')
			this._notifyChange(inst);
	},

	/* Ensure a date is within any min/max bounds. */
	_restrictMinMax: function(inst, date) {
		var minDate = this._getMinMaxDate(inst, 'min');
		var maxDate = this._getMinMaxDate(inst, 'max');
		var newDate = (minDate && date < minDate ? minDate : date);
		newDate = (maxDate && newDate > maxDate ? maxDate : newDate);
		return newDate;
	},

	/* Notify change of month/year. */
	_notifyChange: function(inst) {
		var onChange = this._get(inst, 'onChangeMonthYear');
		if (onChange)
			onChange.apply((inst.input ? inst.input[0] : null),
				[inst.selectedYear, inst.selectedMonth + 1, inst]);
	},

	/* Determine the number of months to show. */
	_getNumberOfMonths: function(inst) {
		var numMonths = this._get(inst, 'numberOfMonths');
		return (numMonths == null ? [1, 1] : (typeof numMonths == 'number' ? [1, numMonths] : numMonths));
	},

	/* Determine the current maximum date - ensure no time components are set. */
	_getMinMaxDate: function(inst, minMax) {
		return this._determineDate(inst, this._get(inst, minMax + 'Date'), null);
	},

	/* Find the number of days in a given month. */
	_getDaysInMonth: function(year, month) {
		return 32 - this._daylightSavingAdjust(new Date(year, month, 32)).getDate();
	},

	/* Find the day of the week of the first of a month. */
	_getFirstDayOfMonth: function(year, month) {
		return new Date(year, month, 1).getDay();
	},

	/* Determines if we should allow a "next/prev" month display change. */
	_canAdjustMonth: function(inst, offset, curYear, curMonth) {
		var numMonths = this._getNumberOfMonths(inst);
		var date = this._daylightSavingAdjust(new Date(curYear,
			curMonth + (offset < 0 ? offset : numMonths[0] * numMonths[1]), 1));
		if (offset < 0)
			date.setDate(this._getDaysInMonth(date.getFullYear(), date.getMonth()));
		return this._isInRange(inst, date);
	},

	/* Is the given date in the accepted range? */
	_isInRange: function(inst, date) {
		var minDate = this._getMinMaxDate(inst, 'min');
		var maxDate = this._getMinMaxDate(inst, 'max');
		return ((!minDate || date.getTime() >= minDate.getTime()) &&
			(!maxDate || date.getTime() <= maxDate.getTime()));
	},

	/* Provide the configuration settings for formatting/parsing. */
	_getFormatConfig: function(inst) {
		var shortYearCutoff = this._get(inst, 'shortYearCutoff');
		shortYearCutoff = (typeof shortYearCutoff != 'string' ? shortYearCutoff :
			new Date().getFullYear() % 100 + parseInt(shortYearCutoff, 10));
		return {shortYearCutoff: shortYearCutoff,
			dayNamesShort: this._get(inst, 'dayNamesShort'), dayNames: this._get(inst, 'dayNames'),
			monthNamesShort: this._get(inst, 'monthNamesShort'), monthNames: this._get(inst, 'monthNames')};
	},

	/* Format the given date for display. */
	_formatDate: function(inst, day, month, year) {
		if (!day) {
			inst.currentDay = inst.selectedDay;
			inst.currentMonth = inst.selectedMonth;
			inst.currentYear = inst.selectedYear;
		}
		var date = (day ? (typeof day == 'object' ? day :
			this._daylightSavingAdjust(new Date(year, month, day))) :
			this._daylightSavingAdjust(new Date(inst.currentYear, inst.currentMonth, inst.currentDay)));
		return this.formatDate(this._get(inst, 'dateFormat'), date, this._getFormatConfig(inst));
	}
});

/*
 * Bind hover events for datepicker elements.
 * Done via delegate so the binding only occurs once in the lifetime of the parent div.
 * Global instActive, set by _updateDatepicker allows the handlers to find their way back to the active picker.
 */ 
function bindHover(dpDiv) {
	var selector = 'button, .ui-datepicker-prev, .ui-datepicker-next, .ui-datepicker-calendar td a';
	return dpDiv.delegate(selector, 'mouseout', function() {
			$(this).removeClass('ui-state-hover');
			if (this.className.indexOf('ui-datepicker-prev') != -1) $(this).removeClass('ui-datepicker-prev-hover');
			if (this.className.indexOf('ui-datepicker-next') != -1) $(this).removeClass('ui-datepicker-next-hover');
		})
		.delegate(selector, 'mouseover', function(){
			if (!$.datepicker._isDisabledDatepicker( instActive.inline ? dpDiv.parent()[0] : instActive.input[0])) {
				$(this).parents('.ui-datepicker-calendar').find('a').removeClass('ui-state-hover');
				$(this).addClass('ui-state-hover');
				if (this.className.indexOf('ui-datepicker-prev') != -1) $(this).addClass('ui-datepicker-prev-hover');
				if (this.className.indexOf('ui-datepicker-next') != -1) $(this).addClass('ui-datepicker-next-hover');
			}
		});
}

/* jQuery extend now ignores nulls! */
function extendRemove(target, props) {
	$.extend(target, props);
	for (var name in props)
		if (props[name] == null || props[name] == undefined)
			target[name] = props[name];
	return target;
};

/* Determine whether an object is an array. */
function isArray(a) {
	return (a && (($.browser.safari && typeof a == 'object' && a.length) ||
		(a.constructor && a.constructor.toString().match(/\Array\(\)/))));
};

/* Invoke the datepicker functionality.
   @param  options  string - a command, optionally followed by additional parameters or
                    Object - settings for attaching new datepicker functionality
   @return  jQuery object */
$.fn.datepicker = function(options){
	
	/* Verify an empty collection wasn't passed - Fixes #6976 */
	if ( !this.length ) {
		return this;
	}
	
	/* Initialise the date picker. */
	if (!$.datepicker.initialized) {
		$(document).mousedown($.datepicker._checkExternalClick).
			find('body').append($.datepicker.dpDiv);
		$.datepicker.initialized = true;
	}

	var otherArgs = Array.prototype.slice.call(arguments, 1);
	if (typeof options == 'string' && (options == 'isDisabled' || options == 'getDate' || options == 'widget'))
		return $.datepicker['_' + options + 'Datepicker'].
			apply($.datepicker, [this[0]].concat(otherArgs));
	if (options == 'option' && arguments.length == 2 && typeof arguments[1] == 'string')
		return $.datepicker['_' + options + 'Datepicker'].
			apply($.datepicker, [this[0]].concat(otherArgs));
	return this.each(function() {
		typeof options == 'string' ?
			$.datepicker['_' + options + 'Datepicker'].
				apply($.datepicker, [this].concat(otherArgs)) :
			$.datepicker._attachDatepicker(this, options);
	});
};

$.datepicker = new Datepicker(); // singleton instance
$.datepicker.initialized = false;
$.datepicker.uuid = new Date().getTime();
$.datepicker.version = "@VERSION";

// Workaround for #4055
// Add another global to avoid noConflict issues with inline event handlers
window['DP_jQuery_' + dpuuid] = $;

})(jQuery);