/**
 * datepicker.js - MooTools Datepicker class
 * @version 1.16
 * 
 * by MonkeyPhysics.com
 *
 * Source/Documentation available at:
 * http://www.monkeyphysics.com/mootools/script/2/datepicker
 * 
 * --
 * 
 * Smoothly animating, very configurable and easy to install.
 * No Ajax, pure Javascript. 4 skins available out of the box.
 * 
 * --
 *
 * Some Rights Reserved
 * http://creativecommons.org/licenses/by-sa/3.0/
 * 
 */

var DatePicker = new Class({
	
	Implements: Options,
	
	// working date, which we will keep modifying to render the calendars
	d: '',
	
	// just so that we need not request it over and over
	today: '',
	
	// current user-choice in date object format
	choice: {}, 
	
	// size of body, used to animate the sliding
	bodysize: {}, 
	
	// to check availability of next/previous buttons
	limit: {}, 
	
	// element references:
	attachTo: null,    // selector for target inputs
	picker: null,      // main datepicker container
	slider: null,      // slider that contains both oldContents and newContents, used to animate between 2 different views
	oldContents: null, // used in animating from-view to new-view
	newContents: null, // used in animating from-view to new-view
	input: null,       // original input element (used for input/output)
	visual: null,      // visible input (used for rendering)
	
	options: { 
		pickerClass: 'datepicker',
		days: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'],
		months: ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'],
		dayShort: 2,
		monthShort: 3,
		startDay: 1, // Sunday (0) through Saturday (6) - be aware that this may affect your layout, since the days on the right might have a different margin
		timePicker: false,
		timePickerOnly: false,
		yearPicker: true,
		yearsPerPage: 20,
		format: 'd-m-Y',
		allowEmpty: false,
		inputOutputFormat: 'U', // default to unix timestamp
		animationDuration: 400,
		useFadeInOut: (Browser.name!='ie'), // dont animate fade-in/fade-out for IE
		startView: 'month', // allowed values: {time, month, year, decades}
		positionOffset: { x: 0, y: 0 },
		minDate: null, // { date: '[date-string]', format: '[date-string-interpretation-format]' }
		maxDate: null, // same as minDate
		debug: false,
		toggleElements: null,
		
		// and some event hooks:
		onShow: function(){},   // triggered when the datepicker pops up
		onClose: function(){},  // triggered after the datepicker is closed (destroyed)
		onSelect: function(){}  // triggered when a date is selected
	},
	
	initialize: function(attachTo, options) {
		this.attachTo = attachTo;
		this.setOptions(options).attach();
		if (this.options.timePickerOnly) {
			this.options.timePicker = true;
			this.options.startView = 'time';
		}
		this.formatMinMaxDates();
		document.addEvent('mousedown', this.close.bind(this));
		return this;
	},
	
	formatMinMaxDates: function() {
		if (this.options.minDate && this.options.minDate.format) {
			this.options.minDate = this.unformat(this.options.minDate.date, this.options.minDate.format);
		}
		if (this.options.maxDate && this.options.maxDate.format) {
			this.options.maxDate = this.unformat(this.options.maxDate.date, this.options.maxDate.format);
			this.options.maxDate.setHours(23);
			this.options.maxDate.setMinutes(59);
			this.options.maxDate.setSeconds(59);
		}
	},
	
	attach: function() {
		// toggle the datepicker through a separate element?
		if (this.options.toggleElements != null) {
			var togglers = $$(this.options.toggleElements);
			document.addEvents({
				'keydown': function(e) {
					if (e.key == "tab") {
						this.close(null, true);
					}
				}.bind(this)
			});
		};
		
		// attach functionality to the inputs		
		$$(this.attachTo).each(function(item, index) {
			// never double attach
			if (item.retrieve('datepicker')) return;
			
			// determine starting value(s)
			if (typeof item.get('value') != undefined && item.get('value')) {
				var init_clone_val = this.format(new Date(this.unformat(item.get('value'), this.options.inputOutputFormat)), this.options.format);
			} else if (!this.options.allowEmpty) {
				var init_clone_val = this.format(new Date(), this.options.format);
			} else {
				var init_clone_val = '';
			}
			
			// create clone
			var display = item.getStyle('display');
			var clone = {};
			
			if ( ! Browser.name=='ie7' )
			{
				clone = item
				.setStyle('display', this.options.debug ? display : 'none')
				.store('datepicker', true) // to prevent double attachment...
				.clone()
				.store('datepicker', true) // ...even for the clone (!)
				.removeProperty('name')    // secure clean (form)submission
				.removeProperty('pattern')    // chrome and safari self-pattern-check
				.setStyle('display', display)
				.set('value', init_clone_val)
				.inject(item, 'before');
			}
			else
			{
				clone = item;
			}
			
			// events
			if (this.options.toggleElements != null) {
				togglers[index]
					.setStyle('cursor', 'pointer')
					.addEvents({
						'click': function(e) {
							this.onFocus(item, clone);
						}.bind(this)
					});
				clone.addEvents({
					'blur': function() {
						item.set('value', clone.get('value'));
					}
				});
			} else {
				clone.addEvents({
					'keydown': function(e) {
						if (this.options.allowEmpty && (e.key == "delete" || e.key == "backspace")) {
							item.set('value', '');
							e.target.set('value', '');
							this.close(null, true);
						} else if (e.key == "tab") {
							this.close(null, true);
						} else {
							e.stop();
						}
					}.bind(this),
					'focus': function(e) {
						this.onFocus(item, clone);
					}.bind(this)
				});
			}
		}.bind(this));
	},
	
	onFocus: function(original_input, visual_input)
	{
		var init_visual_date, d = visual_input.getCoordinates();

		this.originalInput = visual_input;

		if (original_input.get('value') != null) {
			init_visual_date = this.unformat(original_input.get('value'), this.options.inputOutputFormat).valueOf();
		} else {
			init_visual_date = new Date();
			if (this.options.maxDate != null && init_visual_date.valueOf() > this.options.maxDate.valueOf()) {
				init_visual_date = new Date(this.options.maxDate.valueOf());
			}
			if (this.options.minDate != null && init_visual_date.valueOf() < this.options.minDate.valueOf()) {
				init_visual_date = new Date(this.options.minDate.valueOf());
			}
		}

		this.show(init_visual_date);
		this.input = original_input;
		this.visual = visual_input;
		this.options.onShow();
	},

	calcPosition: function(field)
	{
		var d = field.getCoordinates(),
			wc = window.getCoordinates();

		var pos = {
			left: d.left + this.options.positionOffset.x,
			top: d.top + d.height + this.options.positionOffset.y
		};

		if ((d.top + 175) > wc.bottom) {
			pos['top'] = d.top - 170;
		}
		return pos;
	},
	
	dateToObject: function(d) {
		return {
			year: d.getFullYear(),
			month: d.getMonth(),
			day: d.getDate(),
			hours: d.getHours(),
			minutes: d.getMinutes(),
			seconds: d.getSeconds()
		};
	},
	
	dateFromObject: function(values) {
		var d = new Date();
		d.setDate(1);
		['year', 'month', 'day', 'hours', 'minutes', 'seconds'].each(function(type) {
			var v = values[type];
			if (typeof v == undefined || v == null) return;
			switch (type) {
				case 'day': d.setDate(v); break;
				case 'month': d.setMonth(v); break;
				case 'year': d.setFullYear(v); break;
				case 'hours': d.setHours(v); break;
				case 'minutes': d.setMinutes(v); break;
				case 'seconds': d.setSeconds(v); break;
			}
		});
		return d;
	},
	
	show: function(timestamp) {
		this.formatMinMaxDates();
		if (timestamp) {
			this.d = new Date(timestamp);
		} else {
			this.d = new Date();
		}
		this.today = new Date();
		this.choice = this.dateToObject(this.d);
		this.mode = (this.options.startView == 'time' && !this.options.timePicker) ? 'month' : this.options.startView;
		this.render();
	},

	setPosition: function()
	{
		var d = this.originalInput.getCoordinates(),
			p = this.picker.getCoordinates(),
			h = p.height,
			wc = window.getCoordinates();
		var pos = {
			left: d.left + this.options.positionOffset.x,
			top: d.top + d.height + this.options.positionOffset.y
		};

		if ((d.top + (h+30)) > wc.bottom) {
			pos['top'] = d.top - h;
		}
		this.picker.setStyles(pos);
	},

	render: function(fx) {
		if (typeof this.picker == undefined || this.picker == null) {
			this.constructPicker();
		} else {
			// swap contents so we can fill the newContents again and animate
			var o = this.oldContents;
			this.oldContents = this.newContents;
			this.newContents = o;
			this.newContents.empty();
		}

		this.setPosition();

		// remember current working date
		var startDate = new Date(this.d.getTime());
		
		// intially assume both left and right are allowed
		this.limit = { right: false, left: false };
		
		// render! booty!
		if (this.mode == 'decades') {
			this.renderDecades();
		} else if (this.mode == 'year') {
			this.renderYear();
		} else if (this.mode == 'time') {
			this.renderTime();
			this.limit = { right: true, left: true }; // no left/right in timeview
		} else {
			this.renderMonth();
		}
		
		this.picker.getElement('.previous').setStyle('visibility', this.limit.left ? 'hidden' : 'visible');
		this.picker.getElement('.next').setStyle('visibility', this.limit.right ? 'hidden' : 'visible');
		this.picker.getElement('.titleText').setStyle('cursor', this.allowZoomOut() ? 'pointer' : 'default');
		
		// restore working date
		this.d = startDate;
		
		// if ever the opacity is set to '0' it was only to have us fade it in here
		// refer to the constructPicker() function, which instantiates the picker at opacity 0 when fading is desired
		if (this.picker.getStyle('opacity') == 0) {
			this.picker.tween('opacity', 0, 1);
		}
		
		// animate
		if (fx != null) this.fx(fx);
	},
	
	fx: function(fx) {
		if (fx == 'right') {
			this.oldContents.setStyles({ left: 0, opacity: 1 });
			this.newContents.setStyles({ left: this.bodysize.x, opacity: 1 });
			this.slider.setStyle('left', 0).tween('left', 0, -this.bodysize.x);
		} else if (fx == 'left') {
			this.oldContents.setStyles({ left: this.bodysize.x, opacity: 1 });
			this.newContents.setStyles({ left: 0, opacity: 1 });
			this.slider.setStyle('left', -this.bodysize.x).tween('left', -this.bodysize.x, 0);
		} else if (fx == 'fade') {
			this.slider.setStyle('left', 0);
			// this.oldContents.setStyle('left', 0).set('tween', { duration: this.options.animationDuration / 2 }).tween('opacity', 1, 0);
			this.oldContents.setStyle('left', this.bodysize.x).set('tween', { duration: this.options.animationDuration / 2 }).tween('opacity', 1, 0);
			this.newContents.setStyles({ opacity: 0, left: 0}).set('tween', { duration: this.options.animationDuration }).tween('opacity', 0, 1);
		}
	},
	
	constructPicker: function()
	{
		this.picker = new Element('div', { 'class': this.options.pickerClass }).inject(document.body);
		// this.picker = new Element('div', { 'class': this.options.pickerClass }).inject(this.originalInput.getParent());

		if (this.options.useFadeInOut) {
			// add 2 to max z-index, if the layer which contains the calendar set its z-index property after the execution of this line
			this.picker.setStyles({opacity:0,"z-index":this.getMaxZindex()+2}).set('tween', { duration: this.options.animationDuration });
		}
		
		var h = new Element('div', { 'class': 'header' }).inject(this.picker);
		var titlecontainer = new Element('div', { 'class': 'title' }).inject(h);
		new Element('div', { 'class': 'previous' }).addEvent('click', this.previous.bind(this)).set('text', '«').inject(h);
		new Element('div', { 'class': 'next' }).addEvent('click', this.next.bind(this)).set('text', '»').inject(h);
		new Element('div', { 'class': 'closeButton' }).addEvent('click', function(evt) { this.close(evt, true).bind(this); }.bind(this)).set('text', 'x').inject(h);
		new Element('span', { 'class': 'titleText' }).addEvent('click', this.zoomOut.bind(this)).inject(titlecontainer);
		
		var b = new Element('div', { 'class': 'body' }).inject(this.picker);
		this.bodysize = b.getSize();
		this.slider = new Element('div', { styles: { position: 'absolute', top: 0, left: 0, width: 2 * this.bodysize.x, height: this.bodysize.y }})
					.set('tween', { duration: this.options.animationDuration, transition: Fx.Transitions.Quad.easeInOut }).inject(b);
		this.oldContents = new Element('div', { styles: { position: 'absolute', top: 0, left: this.bodysize.x, width: this.bodysize.x, height: this.bodysize.y }}).inject(this.slider);
		this.newContents = new Element('div', { styles: { position: 'absolute', top: 0, left: 0, width: this.bodysize.x, height: this.bodysize.y }}).inject(this.slider);
	},
	
	renderTime: function() {
		var container = new Element('div', { 'class': 'time' }).inject(this.newContents);
		
		if (this.options.timePickerOnly) {
			this.picker.getElement('.titleText').set('text', 'Select a time');
		} else {
			this.picker.getElement('.titleText').set('text', this.format(this.d, 'j M, Y'));
		}
		
		new Element('input', { type: 'text', 'class': 'hour' })
			.set('value', this.leadZero(this.d.getHours()))
			.addEvents({
				mousewheel: function(e) {
					var i = e.target, v = i.get('value').toInt();
					i.focus();
					if (e.wheel > 0) {
						v = (v < 23) ? v + 1 : 0;
					} else {
						v = (v > 0) ? v - 1 : 23;
					}
					i.set('value', this.leadZero(v));
					e.stop();
				}.bind(this)
			})
			.set('maxlength', 2)
			.inject(container);
			
		new Element('input', { type: 'text', 'class': 'minutes' })
			.set('value', this.leadZero(this.d.getMinutes()))
			.addEvents({
				mousewheel: function(e) {
					var i = e.target, v = i.get('value').toInt();
					i.focus();
					if (e.wheel > 0) {
						v = (v < 59) ? v + 1 : 0;
					} else {
						v = (v > 0) ? v - 1 : 59;
					}
					i.set('value', this.leadZero(v));
					e.stop();
				}.bind(this)
			})
			.set('maxlength', 2)
			.inject(container);
		
		new Element('div', { 'class': 'separator' }).set('text', ':').inject(container);
		
		new Element('input', { type: 'submit', value: 'OK', 'class': 'ok' })
			.addEvents({
				click: function(e) {
					e.stop();
					this.select(Object.merge({}, this.dateToObject(this.d), { hours: this.picker.getElement('.hour').get('value').toInt(), minutes: this.picker.getElement('.minutes').get('value').toInt() }));
				}.bind(this)
			})
			.set('maxlength', 2)
			.inject(container);
	},
	
	renderMonth: function() {
		var month = this.d.getMonth();
		
		this.picker.getElement('.titleText').set('text', this.options.months[month] + ' ' + this.d.getFullYear());
		
		this.d.setDate(1);
		while (this.d.getDay() != this.options.startDay) {
			this.d.setDate(this.d.getDate() - 1);
		}
		
		var container = new Element('div', { 'class': 'days' }).inject(this.newContents);
		var titles = new Element('div', { 'class': 'titles' }).inject(container);
		var d, i, classes, e, weekcontainer;

		for (d = this.options.startDay; d < (this.options.startDay + 7); d++) {
			new Element('div', { 'class': 'title day day' + (d % 7) }).set('text', this.options.days[(d % 7)].substring(0,this.options.dayShort)).inject(titles);
		}
		
		var available = false;
		var t = this.today.toDateString();
		var currentChoice = this.dateFromObject(this.choice).toDateString();
		
		for (i = 0; i < 42; i++) {
			classes = [];
			classes.push('day');
			classes.push('day'+this.d.getDay());
			if (this.d.toDateString() == t) classes.push('today');
			if (this.d.toDateString() == currentChoice) classes.push('selected');
			if (this.d.getMonth() != month) classes.push('otherMonth');
			
			if (i % 7 == 0) {
				weekcontainer = new Element('div', { 'class': 'week week'+(Math.floor(i/7)) }).inject(container);
			}
			
			e = new Element('div', { 'class': classes.join(' ') }).set('text', this.d.getDate()).inject(weekcontainer);

			if (this.limited('date')) {
				e.addClass('unavailable');
				if (available) {
					this.limit.right = true;
				} else if (this.d.getMonth() == month) {
					this.limit.left = true;
				}
			} else {
				available = true;
				(function() {
					var day_date = { day: this.d.getDate(), month: this.d.getMonth(), year: this.d.getFullYear() };
				
					e.addEvent('click', function(evt) {
						if (this.options.timePicker) {
							this.d.setDate(day_date.day);
							this.d.setMonth(day_date.month);
							this.d.setFullYear(day_date.year);
							this.mode = 'time';
							this.render('fade');
						} else {
							this.select(day_date);
						}
					}.bind(this));
				}.bind(this))();
			}
			this.d.setDate(this.d.getDate() + 1);
		}
		if (!available) this.limit.right = true;
	},
	
	renderYear: function() {
		var month = this.today.getMonth();
		var thisyear = this.d.getFullYear() == this.today.getFullYear();
		var selectedyear = this.d.getFullYear() == this.choice.year;
		
		this.picker.getElement('.titleText').set('text', this.d.getFullYear());
		this.d.setMonth(0);
		
		var i, e;
		var available = false;
		var container = new Element('div', { 'class': 'months' }).inject(this.newContents);
		
		for (i = 0; i <= 11; i++) {
			e = new Element('div', { 'class': 'month month'+(i+1)+(i == month && thisyear ? ' today' : '')+(i == this.choice.month && selectedyear ? ' selected' : '') })
			.set('text', this.options.monthShort ? this.options.months[i].substring(0, this.options.monthShort) : this.options.months[i]).inject(container);
			
			if (this.limited('month')) {
				e.addClass('unavailable');
				if (available) {
					this.limit.right = true;
				} else {
					this.limit.left = true;
				}
			} else {
				available = true;
				(function() {
					var my_month = i;
					e.addEvent('click', function(e) {
						this.d.setDate(1);
						this.d.setMonth(my_month);
						this.mode = 'month';
						this.render('fade');
					}.bind(this));
				}.bind(this))();
			}
			this.d.setMonth(i);
		}
		if (!available) this.limit.right = true;
	},
	
	renderDecades: function() {
		// start neatly at interval (eg. 1980 instead of 1987)
		while (this.d.getFullYear() % this.options.yearsPerPage > 0) {
			this.d.setFullYear(this.d.getFullYear() - 1);
		}

		this.picker.getElement('.titleText').set('text', this.d.getFullYear() + '-' + (this.d.getFullYear() + this.options.yearsPerPage - 1));
		
		var i, y, e;
		var available = false;
		var container = new Element('div', { 'class': 'years' }).inject(this.newContents);
		
		if (this.options.minDate != null && this.d.getFullYear() <= this.options.minDate.getFullYear()) {
			this.limit.left = true;
		}
		
		for (i = 0; i < this.options.yearsPerPage; i++) {
			y = this.d.getFullYear();
			e = new Element('div', { 'class': 'year year' + i + (y == this.today.getFullYear() ? ' today' : '') + (y == this.choice.year ? ' selected' : '') }).set('text', y).inject(container);
			
			if (this.limited('year')) {
				e.addClass('unavailable');
				if (available) {
					this.limit.right = true;
				} else {
					this.limit.left = true;
				}
			} else {
				available = true;
				(function() {
					var myYear = y;
					e.addEvent('click', function(e) {
						this.d.setFullYear(myYear);
						this.mode = 'year';
						this.render('fade');
					}.bind(this));
				}.bind(this))();
			}
			this.d.setFullYear(this.d.getFullYear() + 1);
		}
		if (!available) {
			this.limit.right = true;
		}
		if (this.options.maxDate != null && this.d.getFullYear() >= this.options.maxDate.getFullYear()) {
			this.limit.right = true;
		}
	},
	
	limited: function(type) {
		var cs = this.options.minDate != null;
		var ce = this.options.maxDate != null; // adjust
		if (!cs && !ce) return false;
		
		switch (type) {
			case 'year':
				return (cs && this.d.getFullYear() < this.options.minDate.getFullYear()) || (ce && this.d.getFullYear() > this.options.maxDate.getFullYear());
				
			case 'month':
				// todo: there has got to be an easier way...?
				var ms = ('' + this.d.getFullYear() + this.leadZero(this.d.getMonth())).toInt();
				return cs && ms < ('' + this.options.minDate.getFullYear() + this.leadZero(this.options.minDate.getMonth())).toInt()
					|| ce && ms > ('' + this.options.maxDate.getFullYear() + this.leadZero(this.options.maxDate.getMonth())).toInt()
				
			case 'date':
				return (cs && this.d < this.options.minDate) || (ce && this.d > this.options.maxDate);
		}
	},
	
	allowZoomOut: function() {
		if (this.mode == 'time' && this.options.timePickerOnly) return false;
		if (this.mode == 'decades') return false;
		if (this.mode == 'year' && !this.options.yearPicker) return false;
		return true;
	},
	
	zoomOut: function() {
		if (!this.allowZoomOut()) return;
		if (this.mode == 'year') {
			this.mode = 'decades';
		} else if (this.mode == 'time') {
			this.mode = 'month';
		} else {
			this.mode = 'year';
		}
		this.render('fade');
	},
	
	previous: function() {
		if (this.mode == 'decades') {
			this.d.setFullYear(this.d.getFullYear() - this.options.yearsPerPage);
		} else if (this.mode == 'year') {
			this.d.setFullYear(this.d.getFullYear() - 1);
		} else if (this.mode == 'month') {
			this.d.setMonth(this.d.getMonth() - 1);
		}
		this.render('left');
	},
	
	next: function() {
		if (this.mode == 'decades') {
			this.d.setFullYear(this.d.getFullYear() + this.options.yearsPerPage);
		} else if (this.mode == 'year') {
			this.d.setFullYear(this.d.getFullYear() + 1);
		} else if (this.mode == 'month') {
			this.d.setMonth(this.d.getMonth() + 1);
		}
		this.render('right');
	},
	
	close: function(e, force) {
		if (typeof $(this.picker) == undefined || $(this.picker) == null) return;
		var clickOutside = (e != null && e.target != this.picker && !(this.picker.contains(e.target) && this.picker != e.target) && e.target != this.visual);
		if (force || clickOutside) {
			if (this.options.useFadeInOut) {
				this.picker.set('tween', { duration: this.options.animationDuration / 2, onComplete: this.destroy.bind(this) }).tween('opacity', 1, 0);
			} else {
				this.destroy();
			}
		}
	},
	
	destroy: function() {
		this.picker.destroy();
		this.picker = null;
		this.options.onClose();
	},
	
	select: function(values) {
		this.choice = Object.merge({}, this.choice, values);
		var d = this.dateFromObject(this.choice);
		this.input.set('value', this.format(d, this.options.inputOutputFormat));
		this.visual.set('value', this.format(d, this.options.format));
		this.options.onSelect(d, this.input);
		this.close(null, true);
	},
	
	leadZero: function(v) {
		return v < 10 ? '0'+v : v;
	},
	
	format: function(t, format) {
		var f = '';
		var h = t.getHours();
		var m = t.getMonth();
		
		for (var i = 0; i < format.length; i++) {
			switch(format.charAt(i)) {
				case '\\': i++; f+= format.charAt(i); break;
				case 'y': f += (100 + t.getYear() + '').substring(1); break
				case 'Y': f += t.getFullYear(); break;
				case 'm': f += this.leadZero(m + 1); break;
				case 'n': f += (m + 1); break;
				case 'M': f += this.options.months[m].substring(0,this.options.monthShort); break;
				case 'F': f += this.options.months[m]; break;
				case 'd': f += this.leadZero(t.getDate()); break;
				case 'j': f += t.getDate(); break;
				case 'D': f += this.options.days[t.getDay()].substring(0,this.options.dayShort); break;
				case 'l': f += this.options.days[t.getDay()]; break;
				case 'G': f += h; break;
				case 'H': f += this.leadZero(h); break;
				case 'g': f += (h % 12 ? h % 12 : 12); break;
				case 'h': f += this.leadZero(h % 12 ? h % 12 : 12); break;
				case 'a': f += (h > 11 ? 'pm' : 'am'); break;
				case 'A': f += (h > 11 ? 'PM' : 'AM'); break;
				case 'i': f += this.leadZero(t.getMinutes()); break;
				case 's': f += this.leadZero(t.getSeconds()); break;
				case 'U': f += Math.floor(t.valueOf() / 1000); break;
				default:  f += format.charAt(i);
			}
		}
		return f;
	},
	
	unformat: function(t, format) {
		var d = new Date();
		var a = {};
		var c, m;
		t = t.toString();
		
		for (var i = 0; i < format.length; i++) {
			c = format.charAt(i);
			switch(c) {
				case '\\': r = null; i++; break;
				case 'y': r = '[0-9]{2}'; break;
				case 'Y': r = '[0-9]{4}'; break;
				case 'm': r = '0[1-9]|1[012]'; break;
				case 'n': r = '[1-9]|1[012]'; break;
				case 'M': r = '[A-Za-z]{'+this.options.monthShort+'}'; break;
				case 'F': r = '[A-Za-z]+'; break;
				case 'd': r = '0[1-9]|[12][0-9]|3[01]'; break;
				case 'j': r = '[1-9]|[12][0-9]|3[01]'; break;
				case 'D': r = '[A-Za-z]{'+this.options.dayShort+'}'; break;
				case 'l': r = '[A-Za-z]+'; break;
				case 'G': 
				case 'H': 
				case 'g': 
				case 'h': r = '[0-9]{1,2}'; break;
				case 'a': r = '(am|pm)'; break;
				case 'A': r = '(AM|PM)'; break;
				case 'i': 
				case 's': r = '[012345][0-9]'; break;
				case 'U': r = '-?[0-9]+$'; break;
				default:  r = null;
			}
			
			if (r != null) {
				m = t.match('^'+r);
				if (m) {
					a[c] = m[0];
					t = t.substring(a[c].length);
				} else {
					if (this.options.debug) alert("Fatal Error in DatePicker\n\nUnexpected format at: '"+t+"' expected format character '"+c+"' (pattern '"+r+"')");
					return d;
				}
			} else {
				t = t.substring(1);
			}
		}
		
		for (c in a) {
			var v = a[c];
			switch(c) {
				case 'y': d.setFullYear(v < 30 ? 2000 + v.toInt() : 1900 + v.toInt()); break; // assume between 1930 - 2029
				case 'Y': d.setFullYear(v); break;
				case 'm':
				case 'n': d.setMonth(v - 1); break;
				// FALL THROUGH NOTICE! "M" has no break, because "v" now is the full month (eg. 'February'), which will work with the next format "F":
				case 'M': v = this.options.months.filter(function(item, index) { return item.substring(0,this.options.monthShort) == v }.bind(this))[0];
				case 'F': d.setMonth(this.options.months.indexOf(v)); break;
				case 'd':
				case 'j': d.setDate(v); break;
				case 'G': 
				case 'H': d.setHours(v); break;
				case 'g': 
				case 'h': if (a['a'] == 'pm' || a['A'] == 'PM') { d.setHours(v == 12 ? 0 : v.toInt() + 12); } else { d.setHours(v); } break;
				case 'i': d.setMinutes(v); break;
				case 's': d.setSeconds(v); break;
				case 'U': d = new Date(v.toInt() * 1000);
			}
		};
		
		return d;
	},

	getMaxZindex: function() {
		var maxZ = 0;
		$$('body *').each(function(el) {if(el.getStyle('z-index').toInt()) maxZ = Math.max(maxZ, el.getStyle('z-index').toInt())});

		return maxZ;
	}
});
