var dateFormat = function() {
		var token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZ]|"[^"]*"|'[^']*'/g,
		timezone = /\b(?:[PMCEA][SDP]T|(?:Pacific|Mountain|Central|Eastern|Atlantic) (?:Standard|Daylight|Prevailing) Time|(?:GMT|UTC)(?:[-+]\d{4})?)\b/g,
		timezoneClip = /[^-+\dA-Z]/g,
		pad = function(val, len) {
			val = String(val);
			len = len || 2;
			while (val.length < len) val = "0" + val;
			return val;
		};

		// Regexes and supporting functions are cached through closure
		return function(date, mask, utc) {
			var dF = dateFormat;

			// You can't provide utc if you skip other args (use the "UTC:" mask prefix)
			if (arguments.length == 1 && (typeof date == "string" || date instanceof String) && !/\d/.test(date)) {
				mask = date;
				date = undefined;
			}

			// Passing date through Date applies Date.parse, if necessary
			date = date ? new Date(date) : new Date();
			if (isNaN(date)) throw new SyntaxError("invalid date");

			mask = String(dF.masks[mask] || mask || dF.masks["default"]);

			// Allow setting the utc argument via the mask
			if (mask.slice(0, 4) == "UTC:") {
				mask = mask.slice(4);
				utc = true;
			}

			var _ = utc ? "getUTC" : "get",
			d = date[_ + "Date"](),
			D = date[_ + "Day"](),
			m = date[_ + "Month"](),
			y = date[_ + "FullYear"](),
			H = date[_ + "Hours"](),
			M = date[_ + "Minutes"](),
			s = date[_ + "Seconds"](),
			L = date[_ + "Milliseconds"](),
			o = utc ? 0 : date.getTimezoneOffset(),
			flags = {
				d: d,
				dd: pad(d),
				ddd: dF.i18n.dayNames[D],
				dddd: dF.i18n.dayNames[D + 7],
				m: m + 1,
				mm: pad(m + 1),
				mmm: dF.i18n.monthNames[m],
				mmmm: dF.i18n.monthNames[m + 12],
				yy: String(y).slice(2),
				yyyy: y,
				h: H % 12 || 12,
				hh: pad(H % 12 || 12),
				H: H,
				HH: pad(H),
				M: M,
				MM: pad(M),
				s: s,
				ss: pad(s),
				l: pad(L, 3),
				L: pad(L > 99 ? Math.round(L / 10) : L),
				t: H < 12 ? "a" : "p",
				tt: H < 12 ? "am" : "pm",
				T: H < 12 ? "A" : "P",
				TT: H < 12 ? "AM" : "PM",
				Z: utc ? "UTC" : (String(date).match(timezone) || [""]).pop().replace(timezoneClip, ""),
				o: (o > 0 ? "-" : "+") + pad(Math.floor(Math.abs(o) / 60) * 100 + Math.abs(o) % 60, 4),
				S: ["th", "st", "nd", "rd"][d % 10 > 3 ? 0 : (d % 100 - d % 10 != 10) * d % 10]
			};

			return mask.replace(token, function($0) {
				return $0 in flags ? flags[$0] : $0.slice(1, $0.length - 1);
			});
		};
	} ();

	// Some common format strings
	dateFormat.masks = {
		"default": "ddd mmm dd yyyy HH:MM:ss",
		shortDate: "m/d/yy",
		mediumDate: "mmm d, yyyy",
		longDate: "mmmm d, yyyy",
		fullDate: "dddd, mmmm d, yyyy",
		shortTime: "h:MM TT",
		mediumTime: "h:MM:ss TT",
		longTime: "h:MM:ss TT Z",
		isoDate: "yyyy-mm-dd",
		isoTime: "HH:MM:ss",
		isoDateTime: "yyyy-mm-dd'T'HH:MM:ss",
		isoUtcDateTime: "UTC:yyyy-mm-dd'T'HH:MM:ss'Z'"
	};

	// Internationalization strings
	dateFormat.i18n = {
		dayNames: [
		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
		"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
	],
		monthNames: [
		"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
		"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"
	]
	};

	// For convenience...
	Date.prototype.format = function(mask, utc) {
		return dateFormat(this, mask, utc);
	};