/*
 * jQuery UI Datepicker
 *
 * Copyright (c) 2006, 2007, 2008 Marc Grabanski
 * Dual licensed under the MIT (MIT-LICENSE.txt)
 * and GPL (GPL-LICENSE.txt) licenses.
 * 
 * http://docs.jquery.com/UI/Datepicker
 *
 * Depends:
 *  ui.core.js
 *
 * Marc Grabanski (m@marcgrabanski.com) and Keith Wood (kbwood@virginbroadband.com.au).
 */
   
(function($) { // hide the namespace

var PROP_NAME = 'datepicker';

/* 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._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._promptClass = 'ui-datepicker-prompt'; // The name of the dialog prompt 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.regional = []; // Available regional settings, indexed by language code
  this.regional[''] = { // Default regional settings
    clearText: 'Clear', // Display text for clear link
    clearStatus: 'Erase the current date', // Status text for clear link
    closeText: 'Close', // Display text for close link
    closeStatus: 'Close without change', // Status text for close link
    prevText: '<Prev', // Display text for previous month link
    prevStatus: 'Show the previous month', // Status text for previous month link
    prevBigText: '<<', // Display text for previous year link
    prevBigStatus: 'Show the previous year', // Status text for previous year link
    nextText: 'Next>', // Display text for next month link
    nextStatus: 'Show the next month', // Status text for next month link
    nextBigText: '>>', // Display text for next year link
    nextBigStatus: 'Show the next year', // Status text for next year link
    currentText: 'Today', // Display text for current month link
    currentStatus: 'Show the current month', // Status 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
    monthStatus: 'Show a different month', // Status text for selecting a month
    yearStatus: 'Show a different year', // Status text for selecting a year
    weekHeader: 'Wk', // Header for the week of the year column
    weekStatus: 'Week of the year', // Status text for the week of the year column
    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
    dayStatus: 'Set DD as first week day', // Status text for the day of the week selection
    dateStatus: 'Select DD, M d', // Status text for the date selection
    dateFormat: 'mm/dd/yy', // See format options on parseDate
    firstDay: 0, // The first day of the week, Sun = 0, Mon = 1, ...
    initStatus: 'Select a date', // Initial Status text on opening
    isRTL: false // True if right-to-left language, false if left-to-right
  };
  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: 'show', // 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
    closeAtTop: true, // True to have the clear/close at the top,
      // false to have them at the bottom
    mandatory: false, // True to hide the Clear link, false to include it
    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
    showBigPrevNext: false, // True to show big prev/next links
    gotoCurrent: false, // True if today link goes back to current selection instead
    changeMonth: true, // True if month can be selected directly, false if only prev/next
    changeYear: true, // True if year can be selected directly, false if only prev/next
    showMonthAfterYear: false, // True if the year select precedes month, false for month then year
    yearRange: '-10:+10', // Range of years to display in drop-down,
      // either relative to current year (-nn:+nn) or absolute (nnnn:nnnn)
    changeFirstDay: true, // True to click on day name to change, false to remain as set
    highlightWeek: false, // True to highlight the selected week
    showOtherMonths: false, // True to show dates in other months, false to leave blank
    showWeeks: false, // True to show week of the year, false to omit
    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
    showStatus: false, // True to show status bar at bottom, false to not show it
    statusForDate: this.dateStatus, // Function to provide status text for a date -
      // takes date and instance as parameters, returns display text
    minDate: null, // The earliest selectable date, or null for no limit
    maxDate: null, // The latest selectable date, or null for no limit
    duration: 'normal', // 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
    rangeSelect: false, // Allows for selecting a date range on one date picker
    rangeSeparator: ' - ', // Text between two dates in a range
    altField: '', // Selector for an alternate field to store selected dates into
    altFormat: '' // The date format to use for the alternate field
  };
  $.extend(this._defaults, this.regional['']);
  this.dpDiv = $('<div id="' + this._mainDivId + '" style="display: none;"></div>');
}

$.extend(Datepicker.prototype, {
  /* Class name added to elements to indicate already configured with a date picker. */
  markerClassName: 'hasDatepicker',

  /* Debug logging (if enabled). */
  log: function () {
    if (this.debug)
      console.log.apply('', arguments);
  },
  
  /* 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 (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)
      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(/([:\[\]\.])/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
      $('<div class="' + this._inlineClass + '"></div>'))};
  },

  /* Attach the date picker to an input field. */
  _connectDatepicker: function(target, inst) {
    var input = $(target);
    if (input.hasClass(this.markerClassName))
      return;
    var appendText = this._get(inst, 'appendText');
    var isRTL = this._get(inst, 'isRTL');
    if (appendText)
      input[isRTL ? 'before' : 'after']('<span class="' + this._appendClass + '">' + appendText + '</span>');
    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');
      var 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 : $('<img/>').attr(
          { src:buttonImage, alt:buttonText, title:buttonText })));
      input[isRTL ? 'before' : 'after'](trigger);
      trigger.click(function() {
        if ($.datepicker._datepickerShowing && $.datepicker._lastInput == target)
          $.datepicker._hideDatepicker();
        else
          $.datepicker._showDatepicker(target);
        return false;
      });
    }
    input.addClass(this.markerClassName).keydown(this._doKeyDown).keypress(this._doKeyPress).
      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);
  },

  /* 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));
    this._updateDatepicker(inst);
  },

  /* Tidy up after displaying the date picker. */
  _inlineShow: function(inst) {
    var numMonths = this._getNumberOfMonths(inst); // fix width for dynamic number of date pickers
    inst.dpDiv.width(numMonths[1] * $('.ui-datepicker', inst.dpDiv[0]).width());
  }, 

  /* Pop-up the date picker in a "dialog" box.
     @param  input     element - ignored
     @param  dateText  string - the initial date to display (in the current format)
     @param  onSelect  function - the function(dateText) 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, dateText, onSelect, settings, pos) {
    var inst = this._dialogInst; // internal instance
    if (!inst) {
      var id = 'dp' + ++this.uuid;
      this._dialogInput = $('<input type="text" id="' + id +
        '" size="1" style="position: absolute; top: -100px;"/>');
      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 || {});
    this._dialogInput.val(dateText);

    this._pos = (pos ? (pos.length ? pos : [pos.pageX, pos.pageY]) : null);
    if (!this._pos) {
      var browserWidth = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
      var browserHeight = window.innerHeight || document.documentElement.clientHeight || document.body.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] + '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 = $(target);
    if (!$target.hasClass(this.markerClassName)) {
      return;
    }
    var nodeName = target.nodeName.toLowerCase();
    $.removeData(target, PROP_NAME);
    if (nodeName == 'input') {
      $target.siblings('.' + this._appendClass).remove().end().
        siblings('.' + this._triggerClass).remove().end().
        removeClass(this.markerClassName).
        unbind('focus', this._showDatepicker).
        unbind('keydown', this._doKeyDown).
        unbind('keypress', this._doKeyPress);
    } 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 = $(target);
    if (!$target.hasClass(this.markerClassName)) {
      return;
    }
    var nodeName = target.nodeName.toLowerCase();
    if (nodeName == 'input') {
    target.disabled = false;
      $target.siblings('button.' + this._triggerClass).
      each(function() { this.disabled = false; }).end().
        siblings('img.' + this._triggerClass).
        css({opacity: '1.0', cursor: ''});
    }
    else if (nodeName == 'div' || nodeName == 'span') {
      $target.children('.' + this._disableClass).remove();
    }
    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 = $(target);
    if (!$target.hasClass(this.markerClassName)) {
      return;
    }
    var nodeName = target.nodeName.toLowerCase();
    if (nodeName == 'input') {
    target.disabled = true;
      $target.siblings('button.' + this._triggerClass).
      each(function() { this.disabled = true; }).end().
        siblings('img.' + this._triggerClass).
        css({opacity: '0.5', cursor: 'default'});
    }
    else if (nodeName == 'div' || nodeName == 'span') {
      var inline = $target.children('.' + this._inlineClass);
      var offset = inline.offset();
      var relOffset = {left: 0, top: 0};
      inline.parents().each(function() {
        if ($(this).css('position') == 'relative') {
          relOffset = $(this).offset();
          return false;
        }
      });
      $target.prepend('<div class="' + this._disableClass + '" style="' +
        ($.browser.msie ? 'background-color: transparent; ' : '') +
        'width: ' + inline.width() + 'px; height: ' + inline.height() +
        'px; left: ' + (offset.left - relOffset.left) +
        'px; top: ' + (offset.top - relOffset.top) + 'px;"></div>');
    }
    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 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
     @param  value   any - the new value for the setting (omit if above is an object) */
  _changeDatepicker: function(target, name, value) {
    var settings = name || {};
    if (typeof name == 'string') {
      settings = {};
      settings[name] = value;
    }
    var inst = this._getInst(target);
    if (inst) {
      if (this._curInst == inst) {
        this._hideDatepicker(null);
      }
      extendRemove(inst.settings, settings);
      var date = new Date();
      extendRemove(inst, {rangeStart: null, // start of range
        endDay: null, endMonth: null, endYear: null, // end of range
        selectedDay: date.getDate(), selectedMonth: date.getMonth(),
        selectedYear: date.getFullYear(), // starting point
        currentDay: date.getDate(), currentMonth: date.getMonth(),
        currentYear: date.getFullYear(), // current selection
        drawMonth: date.getMonth(), drawYear: date.getFullYear()}); // month being drawn
      this._updateDatepicker(inst);
    }
  },

  /* 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
     @param  endDate  Date - the new end date for a range (optional) */
  _setDateDatepicker: function(target, date, endDate) {
    var inst = this._getInst(target);
    if (inst) {
      this._setDate(inst, date, endDate);
      this._updateDatepicker(inst);
    }
  },

  /* Get the date(s) for the first entry in a jQuery selection.
     @param  target  element - the target input field or division or span
     @return Date - the current date or
             Date[2] - the current dates for a range */
  _getDateDatepicker: function(target) {
    var inst = this._getInst(target);
    if (inst && !inst.inline)
      this._setDateFromField(inst); 
    return (inst ? this._getDate(inst) : null);
  },

  /* Handle keystrokes. */
  _doKeyDown: function(e) {
    var inst = $.datepicker._getInst(e.target);
    var handled = true;
    if ($.datepicker._datepickerShowing)
      switch (e.keyCode) {
        case 9:  $.datepicker._hideDatepicker(null, '');
            break; // hide on tab out
        case 13: $.datepicker._selectDay(e.target, inst.selectedMonth, inst.selectedYear,
              $('td.ui-datepicker-days-cell-over', inst.dpDiv)[0]);
            return false; // don't submit the form
            break; // select the value on enter
        case 27: $.datepicker._hideDatepicker(null, $.datepicker._get(inst, 'duration'));
            break; // hide on escape
        case 33: $.datepicker._adjustDate(e.target, (e.ctrlKey ?
              -$.datepicker._get(inst, 'stepBigMonths') :
              -$.datepicker._get(inst, 'stepMonths')), 'M');
            break; // previous month/year on page up/+ ctrl
        case 34: $.datepicker._adjustDate(e.target, (e.ctrlKey ?
              +$.datepicker._get(inst, 'stepBigMonths') :
              +$.datepicker._get(inst, 'stepMonths')), 'M');
            break; // next month/year on page down/+ ctrl
        case 35: if (e.ctrlKey) $.datepicker._clearDate(e.target);
            handled = e.ctrlKey;
            break; // clear on ctrl+end
        case 36: if (e.ctrlKey) $.datepicker._gotoToday(e.target);
            handled = e.ctrlKey;
            break; // current on ctrl+home
        case 37: if (e.ctrlKey) $.datepicker._adjustDate(e.target, -1, 'D');
            handled = e.ctrlKey;
            break; // -1 day on ctrl+left
        case 38: if (e.ctrlKey) $.datepicker._adjustDate(e.target, -7, 'D');
            handled = e.ctrlKey;
            break; // -1 week on ctrl+up
        case 39: if (e.ctrlKey) $.datepicker._adjustDate(e.target, +1, 'D');
            handled = e.ctrlKey;
            break; // +1 day on ctrl+right
        case 40: if (e.ctrlKey) $.datepicker._adjustDate(e.target, +7, 'D');
            handled = e.ctrlKey;
            break; // +1 week on ctrl+down
        default: handled = false;
      }
    else if (e.keyCode == 36 && e.ctrlKey) // display the date picker on ctrl+home
      $.datepicker._showDatepicker(this);
    else
      handled = false;
    if (handled) {
      e.preventDefault();
      e.stopPropagation();
    }
  },

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

  /* Pop-up the date picker for a given input field.
     @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);
    var beforeShow = $.datepicker._get(inst, 'beforeShow');
    extendRemove(inst.settings, (beforeShow ? beforeShow.apply(input, [input, inst]) : {}));
    $.datepicker._hideDatepicker(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;
    inst.rangeStart = null;
    // determine sizing offscreen
    inst.dpDiv.css({position: 'absolute', display: 'block', top: '-1000px'});
    $.datepicker._updateDatepicker(inst);
    // fix width for dynamic number of date pickers
    inst.dpDiv.width($.datepicker._getNumberOfMonths(inst)[1] *
      $('.ui-datepicker', inst.dpDiv[0])[0].offsetWidth);
    // 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') || 'show';
      var duration = $.datepicker._get(inst, 'duration');
      var postProcess = function() {
        $.datepicker._datepickerShowing = true;
        if ($.browser.msie && parseInt($.browser.version) < 7) // fix IE < 7 select problems
          $('iframe.ui-datepicker-cover').css({width: inst.dpDiv.width() + 4,
            height: inst.dpDiv.height() + 4});
      };
      if ($.effects && $.effects[showAnim])
        inst.dpDiv.show(showAnim, $.datepicker._get(inst, 'showOptions'), duration, postProcess);
      else
        inst.dpDiv[showAnim](duration, postProcess);
      if (duration == '')
        postProcess();
      if (inst.input[0].type != 'hidden')
        inst.input[0].focus();
      $.datepicker._curInst = inst;
    }
  },

  /* Generate the date picker content. */
  _updateDatepicker: function(inst) {
    var dims = {width: inst.dpDiv.width() + 4,
      height: inst.dpDiv.height() + 4};
    inst.dpDiv.empty().append(this._generateHTML(inst)).
      find('iframe.ui-datepicker-cover').
      css({width: dims.width, height: dims.height});
    var numMonths = this._getNumberOfMonths(inst);
    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.input && inst.input[0].type != 'hidden')
      $(inst.input[0]).focus();
  },

  /* Check positioning to remain on screen. */
  _checkOffset: function(inst, offset, isFixed) {
    var pos = inst.input ? this._findPos(inst.input[0]) : null;
    var browserWidth = window.innerWidth || document.documentElement.clientWidth;
    var browserHeight = window.innerHeight || document.documentElement.clientHeight;
    var scrollX = document.documentElement.scrollLeft || document.body.scrollLeft;
    var scrollY = document.documentElement.scrollTop || document.body.scrollTop;
    // reposition date picker horizontally if outside the browser window
    if (this._get(inst, 'isRTL') || (offset.left + inst.dpDiv.width() - scrollX) > browserWidth)
      offset.left = Math.max((isFixed ? 0 : scrollX),
        pos[0] + (inst.input ? inst.input.width() : 0) - (isFixed ? scrollX : 0) - inst.dpDiv.width() -
        (isFixed && $.browser.opera ? document.documentElement.scrollLeft : 0));
    else
      offset.left -= (isFixed ? scrollX : 0);
    // reposition date picker vertically if outside the browser window
    if ((offset.top + inst.dpDiv.height() - scrollY) > browserHeight)
      offset.top = Math.max((isFixed ? 0 : scrollY),
        pos[1] - (isFixed ? scrollY : 0) - (this._inDialog ? 0 : inst.dpDiv.height()) -
        (isFixed && $.browser.opera ? document.documentElement.scrollTop : 0));
    else
      offset.top -= (isFixed ? scrollY : 0);
    return offset;
  },
  
  /* Find an object's position on the screen. */
  _findPos: function(obj) {
        while (obj && (obj.type == 'hidden' || obj.nodeType != 1)) {
            obj = obj.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
     @param  duration  string - the duration over which to close the date picker */
  _hideDatepicker: function(input, duration) {
    var inst = this._curInst;
    if (!inst || (input && inst != $.data(input, PROP_NAME)))
      return;
    var rangeSelect = this._get(inst, 'rangeSelect');
    if (rangeSelect && inst.stayOpen)
      this._selectDate('#' + inst.id, this._formatDate(inst,
        inst.currentDay, inst.currentMonth, inst.currentYear));
    inst.stayOpen = false;
    if (this._datepickerShowing) {
      duration = (duration != null ? duration : this._get(inst, 'duration'));
      var showAnim = this._get(inst, 'showAnim');
      var postProcess = function() {
        $.datepicker._tidyDialog(inst);
      };
      if (duration != '' && $.effects && $.effects[showAnim])
        inst.dpDiv.hide(showAnim, $.datepicker._get(inst, 'showOptions'),
          duration, postProcess);
      else
        inst.dpDiv[(duration == '' ? 'hide' : (showAnim == 'slideDown' ? 'slideUp' :
          (showAnim == 'fadeIn' ? 'fadeOut' : 'hide')))](duration, postProcess);
      if (duration == '')
        this._tidyDialog(inst);
      var onClose = this._get(inst, 'onClose');
      if (onClose)
        onClose.apply((inst.input ? inst.input[0] : null),
          [this._getDate(inst), inst]);  // trigger custom callback
      this._datepickerShowing = false;
      this._lastInput = null;
      inst.settings.prompt = null;
      if (this._inDialog) {
        this._dialogInput.css({ position: 'absolute', left: '0', top: '-100px' });
        if ($.blockUI) {
          $.unblockUI();
          $('body').append(this.dpDiv);
        }
      }
      this._inDialog = false;
    }
    this._curInst = null;
  },

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

  /* Close date picker if clicked elsewhere. */
  _checkExternalClick: function(event) {
    if (!$.datepicker._curInst)
      return;
    var $target = $(event.target);
    if (($target.parents('#' + $.datepicker._mainDivId).length == 0) &&
        !$target.hasClass($.datepicker.markerClassName) &&
        !$target.hasClass($.datepicker._triggerClass) &&
        $.datepicker._datepickerShowing && !($.datepicker._inDialog && $.blockUI))
      $.datepicker._hideDatepicker(null, '');
  },

  /* Adjust one of the date sub-fields. */
  _adjustDate: function(id, offset, period) {
    var target = $(id);
    var inst = this._getInst(target[0]);
    this._adjustInstDate(inst, offset, 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._selectingMonthYear = false;
    inst['selected' + (period == 'M' ? 'Month' : 'Year')] =
    inst['draw' + (period == 'M' ? 'Month' : 'Year')] =
      parseInt(select.options[select.selectedIndex].value);
    this._notifyChange(inst);
    this._adjustDate(target);
  },

  /* Restore input focus after not changing month/year. */
  _clickMonthYear: function(id) {
    var target = $(id);
    var inst = this._getInst(target[0]);
    if (inst.input && inst._selectingMonthYear && !$.browser.msie)
      inst.input[0].focus();
    inst._selectingMonthYear = !inst._selectingMonthYear;
  },

  /* Action for changing the first week day. */
  _changeFirstDay: function(id, day) {
    var target = $(id);
    var inst = this._getInst(target[0]);
    inst.settings.firstDay = day;
    this._updateDatepicker(inst);
  },

  /* Action for selecting a day. */
  _selectDay: function(id, month, year, td) {
    if ($(td).hasClass(this._unselectableClass))
      return;
    var target = $(id);
    var inst = this._getInst(target[0]);
    var rangeSelect = this._get(inst, 'rangeSelect');
    if (rangeSelect) {
      inst.stayOpen = !inst.stayOpen;
      if (inst.stayOpen) {
        $('.ui-datepicker td', inst.dpDiv).removeClass(this._currentClass);
        $(td).addClass(this._currentClass);
      } 
    }
    inst.selectedDay = inst.currentDay = $('a', td).html();
    inst.selectedMonth = inst.currentMonth = month;
    inst.selectedYear = inst.currentYear = year;
    if (inst.stayOpen) {
      inst.endDay = inst.endMonth = inst.endYear = null;
    }
    else if (rangeSelect) {
      inst.endDay = inst.currentDay;
      inst.endMonth = inst.currentMonth;
      inst.endYear = inst.currentYear;
    }
    this._selectDate(id, this._formatDate(inst,
      inst.currentDay, inst.currentMonth, inst.currentYear));
    if (inst.stayOpen) {
      inst.rangeStart = new Date(inst.currentYear, inst.currentMonth, inst.currentDay);
      this._updateDatepicker(inst);
    }
    else if (rangeSelect) {
      inst.selectedDay = inst.currentDay = inst.rangeStart.getDate();
      inst.selectedMonth = inst.currentMonth = inst.rangeStart.getMonth();
      inst.selectedYear = inst.currentYear = inst.rangeStart.getFullYear();
      inst.rangeStart = null;
      if (inst.inline)
        this._updateDatepicker(inst);
    }
  },

  /* Erase the input field and hide the date picker. */
  _clearDate: function(id) {
    var target = $(id);
    var inst = this._getInst(target[0]);
    if (this._get(inst, 'mandatory'))
      return;
    inst.stayOpen = false;
    inst.endDay = inst.endMonth = inst.endYear = inst.rangeStart = null;
    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 (this._get(inst, 'rangeSelect') && dateStr)
      dateStr = (inst.rangeStart ? this._formatDate(inst, inst.rangeStart) :
        dateStr) + this._get(inst, 'rangeSeparator') + dateStr;
    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 if (!inst.stayOpen) {
      this._hideDatepicker(null, this._get(inst, 'duration'));
      this._lastInput = inst.input[0];
      if (typeof(inst.input[0]) != 'object')
        inst.input[0].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');
      var date = this._getDate(inst);
      dateStr = (isArray(date) ? (!date[0] && !date[1] ? '' :
        this.formatDate(altFormat, date[0], this._getFormatConfig(inst)) +
        this._get(inst, 'rangeSeparator') + this.formatDate(
        altFormat, date[1] || date[0], this._getFormatConfig(inst))) :
        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.getFullYear(), date.getMonth(), date.getDate(),
      (date.getTimezoneOffset() / -60));
    var firstMon = new Date(checkDate.getFullYear(), 1 - 1, 4); // First week always contains 4 Jan
    var firstDay = firstMon.getDay() || 7; // Day of week: Mon = 1, ..., Sun = 7
    firstMon.setDate(firstMon.getDate() + 1 - firstDay); // Preceding Monday
    if (firstDay < 4 && checkDate < firstMon) { // Adjust first three days in year if necessary
      checkDate.setDate(checkDate.getDate() - 3); // Generate for previous year
      return $.datepicker.iso8601Week(checkDate);
    } else if (checkDate > new Date(checkDate.getFullYear(), 12 - 1, 28)) { // Check last three days in year
      firstDay = new Date(checkDate.getFullYear() + 1, 1 - 1, 4).getDay() || 7;
      if (firstDay > 4 && (checkDate.getDay() || 7) < firstDay - 3) { // Adjust if necessary
        return 1;
      }
    }
    return Math.floor(((checkDate - firstMon) / 86400000) / 7) + 1; // Weeks to given date
  },
  
  /* Provide status text for a particular date.
     @param  date  the date to get the status for
     @param  inst  the current datepicker instance
     @return  the status display text for this date */
  dateStatus: function(date, inst) {
    return $.datepicker.formatDate($.datepicker._get(inst, 'dateStatus'),
      date, $.datepicker._getFormatConfig(inst));
  },

  /* 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;
    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) {
      lookAhead(match);
      var origSize = (match == '@' ? 14 : (match == 'y' ? 4 : (match == 'o' ? 3 : 2)));
      var size = origSize;
      var num = 0;
      while (size > 0 && iValue < value.length &&
          value.charAt(iValue) >= '0' && value.charAt(iValue) <= '9') {
        num = num * 10 + parseInt(value.charAt(iValue++));
        size--;
      }
      if (size == origSize)
        throw 'Missing number at position ' + iValue;
      return num;
    };
    // Extract a name from the string value and convert to an index
    var getName = function(match, shortNames, longNames) {
      var names = (lookAhead(match) ? longNames : shortNames);
      var size = 0;
      for (var j = 0; j < names.length; j++)
        size = Math.max(size, names[j].length);
      var name = '';
      var iInit = iValue;
      while (size > 0 && iValue < value.length) {
        name += value.charAt(iValue++);
        for (var i = 0; i < names.length; i++)
          if (name == names[i])
            return i + 1;
        size--;
      }
      throw 'Unknown name at position ' + iInit;
    };
    // 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 "'":
            if (lookAhead("'"))
              checkLiteral();
            else
              literal = true;
            break;
          default:
            checkLiteral();
        }
    }
    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 = new Date(year, month - 1, day);
    if (date.getFullYear() != year || date.getMonth() + 1 != month || date.getDate() != day)
      throw 'Invalid date'; // E.g. 31/02/*
    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
  TIMESTAMP: '@',
  W3C: 'yy-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
     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)
     '...' - 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':
              var doy = date.getDate();
              for (var m = date.getMonth() - 1; m >= 0; m--)
                doy += this._getDaysInMonth(date.getFullYear(), m);
              output += formatNumber('o', doy, 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 "'":
              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;
    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) {
    var dateFormat = this._get(inst, 'dateFormat');
    var dates = inst.input ? inst.input.val().split(this._get(inst, 'rangeSeparator')) : null; 
    inst.endDay = inst.endMonth = inst.endYear = null;
    var date = defaultDate = this._getDefaultDate(inst);
    if (dates.length > 0) {
      var settings = this._getFormatConfig(inst);
      if (dates.length > 1) {
        date = this.parseDate(dateFormat, dates[1], settings) || defaultDate;
        inst.endDay = date.getDate();
        inst.endMonth = date.getMonth();
        inst.endYear = date.getFullYear();
      }
      try {
        date = this.parseDate(dateFormat, dates[0], settings) || defaultDate;
      } catch (e) {
        this.log(e);
        date = defaultDate;
      }
    }
    inst.selectedDay = date.getDate();
    inst.drawMonth = inst.selectedMonth = date.getMonth();
    inst.drawYear = inst.selectedYear = date.getFullYear();
    inst.currentDay = (dates[0] ? date.getDate() : 0);
    inst.currentMonth = (dates[0] ? date.getMonth() : 0);
    inst.currentYear = (dates[0] ? date.getFullYear() : 0);
    this._adjustInstDate(inst);
  },
  
  /* Retrieve the default date shown on opening. */
  _getDefaultDate: function(inst) {
    var date = this._determineDate(this._get(inst, 'defaultDate'), new Date());
    var minDate = this._getMinMaxDate(inst, 'min', true);
    var maxDate = this._getMinMaxDate(inst, 'max');
    date = (minDate && date < minDate ? minDate : date);
    date = (maxDate && date > maxDate ? maxDate : date);
    return date;
  },

  /* A date may be specified as an exact value or a relative one. */
  _determineDate: function(date, defaultDate) {
    var offsetNumeric = function(offset) {
      var date = new Date();
      date.setUTCDate(date.getUTCDate() + offset);
      return date;
    };
    var offsetString = function(offset, getDaysInMonth) {
      var date = 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]); break;
          case 'w' : case 'W' :
            day += parseInt(matches[1]) * 7; break;
          case 'm' : case 'M' :
            month += parseInt(matches[1]); 
            day = Math.min(day, getDaysInMonth(year, month));
            break;
          case 'y': case 'Y' :
            year += parseInt(matches[1]);
            day = Math.min(day, getDaysInMonth(year, month));
            break;
        }
        matches = pattern.exec(offset);
      }
      return new Date(year, month, day);
    };
    date = (date == null ? defaultDate :
      (typeof date == 'string' ? offsetString(date, this._getDaysInMonth) :
      (typeof date == 'number' ? (isNaN(date) ? defaultDate : offsetNumeric(date)) : date)));
    return (date && date.toString() == 'Invalid Date' ? defaultDate : date);
  },

  /* Set the date(s) directly. */
  _setDate: function(inst, date, endDate) {
    var clear = !(date);
    var origMonth = inst.selectedMonth;
    var origYear = inst.selectedYear;
    date = this._determineDate(date, new Date());
    inst.selectedDay = inst.currentDay = date.getDate();
    inst.drawMonth = inst.selectedMonth = inst.currentMonth = date.getMonth();
    inst.drawYear = inst.selectedYear = inst.currentYear = date.getFullYear();
    if (this._get(inst, 'rangeSelect')) {
      if (endDate) {
        endDate = this._determineDate(endDate, null);
        inst.endDay = endDate.getDate();
        inst.endMonth = endDate.getMonth();
        inst.endYear = endDate.getFullYear();
      } else {
        inst.endDay = inst.currentDay;
        inst.endMonth = inst.currentMonth;
        inst.endYear = inst.currentYear;
      }
    }
    if (origMonth != inst.selectedMonth || origYear != inst.selectedYear)
      this._notifyChange(inst);
    this._adjustInstDate(inst);
    if (inst.input)
      inst.input.val(clear ? '' : this._formatDate(inst) +
        (!this._get(inst, 'rangeSelect') ? '' : this._get(inst, 'rangeSeparator') +
        this._formatDate(inst, inst.endDay, inst.endMonth, inst.endYear)));
  },

  /* Retrieve the date(s) directly. */
  _getDate: function(inst) {
    var startDate = (!inst.currentYear || (inst.input && inst.input.val() == '') ? null :
      new Date(inst.currentYear, inst.currentMonth, inst.currentDay));
    if (this._get(inst, 'rangeSelect')) {
      return [inst.rangeStart || startDate,
        (!inst.endYear ? inst.rangeStart || startDate :
        new Date(inst.endYear, inst.endMonth, inst.endDay))];
    } else
      return startDate;
  },

  /* Generate the HTML for the current state of the date picker. */
  _generateHTML: function(inst) {
    var today = new Date();
    today = new Date(today.getFullYear(), today.getMonth(), today.getDate()); // clear time
    var showStatus = this._get(inst, 'showStatus');
    var initStatus = this._get(inst, 'initStatus') || '&#xa0;';
    var isRTL = this._get(inst, 'isRTL');
    // build the date picker HTML
    var clear = (this._get(inst, 'mandatory') ? '' :
      '<div class="ui-datepicker-clear"><a onclick="jQuery.datepicker._clearDate(\'#' + inst.id + '\');"' +
      this._addStatus(showStatus, inst.id, this._get(inst, 'clearStatus'), initStatus) + '>' +
      this._get(inst, 'clearText') + '</a></div>');
    var controls = '<div class="ui-datepicker-control">' + (isRTL ? '' : clear) +
      '<div class="ui-datepicker-close"><a onclick="jQuery.datepicker._hideDatepicker();"' +
      this._addStatus(showStatus, inst.id, this._get(inst, 'closeStatus'), initStatus) + '>' +
      this._get(inst, 'closeText') + '</a></div>' + (isRTL ? clear : '')  + '</div>';
    var prompt = this._get(inst, 'prompt');
    var closeAtTop = this._get(inst, 'closeAtTop');
    var hideIfNoPrevNext = this._get(inst, 'hideIfNoPrevNext');
    var navigationAsDateFormat = this._get(inst, 'navigationAsDateFormat');
    var showBigPrevNext = this._get(inst, 'showBigPrevNext');
    var numMonths = this._getNumberOfMonths(inst);
    var showCurrentAtPos = this._get(inst, 'showCurrentAtPos');
    var stepMonths = this._get(inst, 'stepMonths');
    var stepBigMonths = this._get(inst, 'stepBigMonths');
    var isMultiMonth = (numMonths[0] != 1 || numMonths[1] != 1);
    var currentDate = (!inst.currentDay ? new Date(9999, 9, 9) :
      new Date(inst.currentYear, inst.currentMonth, inst.currentDay));
    var minDate = this._getMinMaxDate(inst, 'min', true);
    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 = new Date(maxDate.getFullYear(),
        maxDate.getMonth() - numMonths[1] + 1, maxDate.getDate());
      maxDraw = (minDate && maxDraw < minDate ? minDate : maxDraw);
      while (new Date(drawYear, drawMonth, 1) > maxDraw) {
        drawMonth--;
        if (drawMonth < 0) {
          drawMonth = 11;
          drawYear--;
        }
      }
    }
    // controls and links
    var prevText = this._get(inst, 'prevText');
    prevText = (!navigationAsDateFormat ? prevText : this.formatDate(
      prevText, new Date(drawYear, drawMonth - stepMonths, 1), this._getFormatConfig(inst)));
    var prevBigText = (showBigPrevNext ? this._get(inst, 'prevBigText') : '');
    prevBigText = (!navigationAsDateFormat ? prevBigText : this.formatDate(
      prevBigText, new Date(drawYear, drawMonth - stepBigMonths, 1), this._getFormatConfig(inst)));
    var prev = '<div class="ui-datepicker-prev">' + (this._canAdjustMonth(inst, -1, drawYear, drawMonth) ? 
      (showBigPrevNext ? '<a onclick="jQuery.datepicker._adjustDate(\'#' + inst.id + '\', -' + stepBigMonths + ', \'M\');"' +
      this._addStatus(showStatus, inst.id, this._get(inst, 'prevBigStatus'), initStatus) + '>' + prevBigText + '</a>' : '') +
      '<a onclick="jQuery.datepicker._adjustDate(\'#' + inst.id + '\', -' + stepMonths + ', \'M\');"' +
      this._addStatus(showStatus, inst.id, this._get(inst, 'prevStatus'), initStatus) + '>' + prevText + '</a>' :
      (hideIfNoPrevNext ? '' : '<label>' + prevBigText + '</label><label>' + prevText + '</label>')) + '</div>';
    var nextText = this._get(inst, 'nextText');
    nextText = (!navigationAsDateFormat ? nextText : this.formatDate(
      nextText, new Date(drawYear, drawMonth + stepMonths, 1), this._getFormatConfig(inst)));
    var nextBigText = (showBigPrevNext ? this._get(inst, 'nextBigText') : '');
    nextBigText = (!navigationAsDateFormat ? nextBigText : this.formatDate(
      nextBigText, new Date(drawYear, drawMonth + stepBigMonths, 1), this._getFormatConfig(inst)));
    var next = '<div class="ui-datepicker-next">' + (this._canAdjustMonth(inst, +1, drawYear, drawMonth) ?
      '<a onclick="jQuery.datepicker._adjustDate(\'#' + inst.id + '\', +' + stepMonths + ', \'M\');"' +
      this._addStatus(showStatus, inst.id, this._get(inst, 'nextStatus'), initStatus) + '>' + nextText + '</a>' +
      (showBigPrevNext ? '<a onclick="jQuery.datepicker._adjustDate(\'#' + inst.id + '\', +' + stepBigMonths + ', \'M\');"' +
      this._addStatus(showStatus, inst.id, this._get(inst, 'nextBigStatus'), initStatus) + '>' + nextBigText + '</a>' : '') :
      (hideIfNoPrevNext ? '' : '<label>' + nextText + '</label><label>' + nextBigText + '</label>')) + '</div>';
    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 html = (prompt ? '<div class="' + this._promptClass + '">' + prompt + '</div>' : '') +
      (closeAtTop && !inst.inline ? controls : '') +
      '<div class="ui-datepicker-links">' + (isRTL ? next : prev) +
      (this._isInRange(inst, gotoDate) ? '<div class="ui-datepicker-current">' +
      '<a onclick="jQuery.datepicker._gotoToday(\'#' + inst.id + '\');"' +
      this._addStatus(showStatus, inst.id, this._get(inst, 'currentStatus'), initStatus) + '>' +
      currentText + '</a></div>' : '') + (isRTL ? prev : next) + '</div>';
    var firstDay = this._get(inst, 'firstDay');
    var changeFirstDay = this._get(inst, 'changeFirstDay');
    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 beforeShowDay = this._get(inst, 'beforeShowDay');
    var highlightWeek = this._get(inst, 'highlightWeek');
    var showOtherMonths = this._get(inst, 'showOtherMonths');
    var showWeeks = this._get(inst, 'showWeeks');
    var calculateWeek = this._get(inst, 'calculateWeek') || this.iso8601Week;
    var weekStatus = this._get(inst, 'weekStatus');
    var status = (showStatus ? this._get(inst, 'dayStatus') || initStatus : '');
    var dateStatus = this._get(inst, 'statusForDate') || this.dateStatus;
    var endDate = inst.endDay ? new Date(inst.endYear, inst.endMonth, inst.endDay) : currentDate;
    for (var row = 0; row < numMonths[0]; row++)
      for (var col = 0; col < numMonths[1]; col++) {
        var selectedDate = new Date(drawYear, drawMonth, inst.selectedDay);
        html += '<div class="ui-datepicker-one-month' + (col == 0 ? ' ui-datepicker-new-row' : '') + '">' +
          this._generateMonthYearHeader(inst, drawMonth, drawYear, minDate, maxDate,
          selectedDate, row > 0 || col > 0, showStatus, initStatus, monthNames) + // draw month headers
          '<table class="ui-datepicker" cellpadding="0" cellspacing="0"><thead>' + 
          '<tr class="ui-datepicker-title-row">' +
          (showWeeks ? '<td' + this._addStatus(showStatus, inst.id, weekStatus, initStatus) + '>' +
          this._get(inst, 'weekHeader') + '</td>' : '');
        for (var dow = 0; dow < 7; dow++) { // days of the week
          var day = (dow + firstDay) % 7;
          var dayStatus = (status.indexOf('DD') > -1 ? status.replace(/DD/, dayNames[day]) :
            status.replace(/D/, dayNamesShort[day]));
          html += '<td' + ((dow + firstDay + 6) % 7 >= 5 ? ' class="ui-datepicker-week-end-cell"' : '') + '>' +
            (!changeFirstDay ? '<span' :
            '<a onclick="jQuery.datepicker._changeFirstDay(\'#' + inst.id + '\', ' + day + ');"') + 
            this._addStatus(showStatus, inst.id, dayStatus, initStatus) + ' title="' + dayNames[day] + '">' +
            dayNamesMin[day] + (changeFirstDay ? '</a>' : '</span>') + '</td>';
        }
        html += '</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 tzDate = new Date(drawYear, drawMonth, 1 - leadDays);
        var utcDate = new Date(drawYear, drawMonth, 1 - leadDays);
        var printDate = utcDate;
        var numRows = (isMultiMonth ? 6 : Math.ceil((leadDays + daysInMonth) / 7)); // calculate the number of rows to generate
        for (var dRow = 0; dRow < numRows; dRow++) { // create date picker rows
          html += '<tr class="ui-datepicker-days-row">' +
            (showWeeks ? '<td class="ui-datepicker-week-col"' +
            this._addStatus(showStatus, inst.id, weekStatus, initStatus) + '>' +
            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 || !daySettings[0] ||
              (minDate && printDate < minDate) || (maxDate && printDate > maxDate);
            html += '<td class="ui-datepicker-days-cell' +
              ((dow + firstDay + 6) % 7 >= 5 ? ' ui-datepicker-week-end-cell' : '') + // highlight weekends
              (otherMonth ? ' ui-datepicker-other-month' : '') + // highlight days from other months
              (printDate.getTime() == selectedDate.getTime() && drawMonth == inst.selectedMonth ?
              ' ui-datepicker-days-cell-over' : '') + // highlight selected day
              (unselectable ? ' ' + this._unselectableClass : '') +  // highlight unselectable days
              (otherMonth && !showOtherMonths ? '' : ' ' + daySettings[1] + // highlight custom dates
              (printDate.getTime() >= currentDate.getTime() && printDate.getTime() <= endDate.getTime() ?  // in current range
              ' ' + 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 ? (highlightWeek ? ' onmouseover="jQuery(this).parent().addClass(\'ui-datepicker-week-over\');"' + // highlight selection week
              ' onmouseout="jQuery(this).parent().removeClass(\'ui-datepicker-week-over\');"' : '') : // unhighlight selection week
              ' onmouseover="jQuery(this).addClass(\'ui-datepicker-days-cell-over\')' + // highlight selection
              (highlightWeek ? '.parent().addClass(\'ui-datepicker-week-over\')' : '') + ';' + // highlight selection week
              (!showStatus || (otherMonth && !showOtherMonths) ? '' : 'jQuery(\'#ui-datepicker-status-' +
              inst.id + '\').html(\'' + (dateStatus.apply((inst.input ? inst.input[0] : null),
              [printDate, inst]) || initStatus) +'\');') + '"' +
              ' onmouseout="jQuery(this).removeClass(\'ui-datepicker-days-cell-over\')' + // unhighlight selection
              (highlightWeek ? '.parent().removeClass(\'ui-datepicker-week-over\')' : '') + ';' + // unhighlight selection week
              (!showStatus || (otherMonth && !showOtherMonths) ? '' : 'jQuery(\'#ui-datepicker-status-' +
              inst.id + '\').html(\'' + initStatus + '\');') + '" onclick="jQuery.datepicker._selectDay(\'#' +
              inst.id + '\',' + drawMonth + ',' + drawYear + ', this);"') + '>' + // actions
              (otherMonth ? (showOtherMonths ? printDate.getDate() : '&#xa0;') : // display for other months
              (unselectable ? printDate.getDate() : '<a>' + printDate.getDate() + '</a>')) + '</td>'; // display for this month
            tzDate.setDate(tzDate.getDate() + 1);
            utcDate.setUTCDate(utcDate.getUTCDate() + 1);
            printDate = (tzDate > utcDate ? tzDate : utcDate);
          }
          html += '</tr>';
        }
        drawMonth++;
        if (drawMonth > 11) {
          drawMonth = 0;
          drawYear++;
        }
        html += '</tbody></table></div>';
      }
    html += (showStatus ? '<div style="clear: both;"></div><div id="ui-datepicker-status-' + inst.id + 
      '" class="ui-datepicker-status">' + initStatus + '</div>' : '') +
      (!closeAtTop && !inst.inline ? controls : '') +
      '<div style="clear: both;"></div>' + 
      ($.browser.msie && parseInt($.browser.version) < 7 && !inst.inline ? 
      '<iframe src="javascript:false;" class="ui-datepicker-cover"></iframe>' : '');
    return html;
  },
  
  /* Generate the month and year header. */
  _generateMonthYearHeader: function(inst, drawMonth, drawYear, minDate, maxDate,
      selectedDate, secondary, showStatus, initStatus, monthNames) {
    minDate = (inst.rangeStart && minDate && selectedDate < minDate ? selectedDate : minDate);
    var showMonthAfterYear = this._get(inst, 'showMonthAfterYear');
    var html = '<div class="ui-datepicker-header">';
    var monthHtml = '';
    // month selection
    if (secondary || !this._get(inst, 'changeMonth'))
      monthHtml += monthNames[drawMonth] + '&#xa0;';
    else {
      var inMinYear = (minDate && minDate.getFullYear() == drawYear);
      var inMaxYear = (maxDate && maxDate.getFullYear() == drawYear);
      monthHtml += '<select class="ui-datepicker-new-month" ' +
        'onchange="jQuery.datepicker._selectMonthYear(\'#' + inst.id + '\', this, \'M\');" ' +
        'onclick="jQuery.datepicker._clickMonthYear(\'#' + inst.id + '\');"' +
        this._addStatus(showStatus, inst.id, this._get(inst, 'monthStatus'), initStatus) + '>';
      for (var month = 0; month < 12; month++) {
        if ((!inMinYear || month >= minDate.getMonth()) &&
            (!inMaxYear || month <= maxDate.getMonth()))
          monthHtml += '<option value="' + month + '"' +
            (month == drawMonth ? ' selected="selected"' : '') +
            '>' + monthNames[month] + '</option>';
      }
      monthHtml += '</select>';
    }
    if (!showMonthAfterYear)
      html += monthHtml;
    // year selection
    if (secondary || !this._get(inst, 'changeYear'))
      html += drawYear;
    else {
      // determine range of years to display
      var years = this._get(inst, 'yearRange').split(':');
      var year = 0;
      var endYear = 0;
      if (years.length != 2) {
        year = drawYear - 10;
        endYear = drawYear + 10;
      } else if (years[0].charAt(0) == '+' || years[0].charAt(0) == '-') {
        year = endYear = new Date().getFullYear();
        year += parseInt(years[0], 10);
        endYear += parseInt(years[1], 10);
      } else {
        year = parseInt(years[0], 10);
        endYear = parseInt(years[1], 10);
      }
      year = (minDate ? Math.max(year, minDate.getFullYear()) : year);
      endYear = (maxDate ? Math.min(endYear, maxDate.getFullYear()) : endYear);
      html += '<select class="ui-datepicker-new-year" ' +
        'onchange="jQuery.datepicker._selectMonthYear(\'#' + inst.id + '\', this, \'Y\');" ' +
        'onclick="jQuery.datepicker._clickMonthYear(\'#' + inst.id + '\');"' +
        this._addStatus(showStatus, inst.id, this._get(inst, 'yearStatus'), initStatus) + '>';
      for (; year <= endYear; year++) {
        html += '<option value="' + year + '"' +
          (year == drawYear ? ' selected="selected"' : '') +
          '>' + year + '</option>';
      }
      html += '</select>';
    }
    if (showMonthAfterYear)
      html += monthHtml;
    html += '</div>'; // Close datepicker_header
    return html;
  },

  /* Provide code to set and clear the status panel. */
  _addStatus: function(showStatus, id, text, initStatus) {
    return (showStatus ? ' onmouseover="jQuery(\'#ui-datepicker-status-' + id +
      '\').html(\'' + (text || initStatus) + '\');" ' +
      'onmouseout="jQuery(\'#ui-datepicker-status-' + id +
      '\').html(\'' + initStatus + '\');"' : '');
  },

  /* 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 = new Date(year, month, day);
    // ensure it is within the bounds set
    var minDate = this._getMinMaxDate(inst, 'min', true);
    var maxDate = this._getMinMaxDate(inst, 'max');
    date = (minDate && date < minDate ? minDate : date);
    date = (maxDate && date > maxDate ? maxDate : date);
    inst.selectedDay = date.getDate();
    inst.drawMonth = inst.selectedMonth = date.getMonth();
    inst.drawYear = inst.selectedYear = date.getFullYear();
    if (period == 'M' || period == 'Y')
      this._notifyChange(inst);
  },

  /* Notify change of month/year. */
  _notifyChange: function(inst) {
    var onChange = this._get(inst, 'onChangeMonthYear');
    if (onChange)
      onChange.apply((inst.input ? inst.input[0] : null),
        [new Date(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 - may be overridden for a range. */
  _getMinMaxDate: function(inst, minMax, checkRange) {
    var date = this._determineDate(this._get(inst, minMax + 'Date'), null);
    if (date) {
      date.setHours(0);
      date.setMinutes(0);
      date.setSeconds(0);
      date.setMilliseconds(0);
    }
    return (!checkRange || !inst.rangeStart ? date :
      (!date || inst.rangeStart > date ? inst.rangeStart : date));
  },

  /* Find the number of days in a given month. */
  _getDaysInMonth: function(year, month) {
    return 32 - 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 = new Date(curYear, curMonth + (offset < 0 ? offset : 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) {
    // during range selection, use minimum of selected date and range start
    var newMinDate = (!inst.rangeStart ? null :
      new Date(inst.selectedYear, inst.selectedMonth, inst.selectedDay));
    newMinDate = (newMinDate && inst.rangeStart < newMinDate ? inst.rangeStart : newMinDate);
    var minDate = newMinDate || this._getMinMaxDate(inst, 'min');
    var maxDate = this._getMinMaxDate(inst, 'max');
    return ((!minDate || date >= minDate) && (!maxDate || date <= maxDate));
  },
  
  /* 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 : new Date(year, month, day)) :
      new Date(inst.currentYear, inst.currentMonth, inst.currentDay));
    return this.formatDate(this._get(inst, 'dateFormat'), date, this._getFormatConfig(inst));
  }
});

/* 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){
  
  /* Initialise the date picker. */
  if (!$.datepicker.initialized) {
    $(document.body).append($.datepicker.dpDiv).
      mousedown($.datepicker._checkExternalClick);
    $.datepicker.initialized = true;
  }
  
  var otherArgs = Array.prototype.slice.call(arguments, 1);
  if (typeof options == 'string' && (options == 'isDisabled' || options == 'getDate'))
    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();

})(jQuery);