DateFormat = Class.create();
Object.extend(DateFormat, {
    MONTH_NAMES: ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December', 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
    DAY_NAMES: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'],
    LZ: function (x) { return (x < 0 || x > 9 ? "" : "0") + x },
    compareDates: function (date1, dateformat1, date2, dateformat2) {
        var d1 = DateFormat.parseFormat(date1, dateformat1);
        var d2 = DateFormat.parseFormat(date2, dateformat2);
        if (d1 == 0 || d2 == 0) return -1;
        else if (d1 > d2) return 1;
        return 0;
    },
    format: function (date, format) {
        format = format + "";
        var result = "";
        var i_format = 0;
        var c = "";
        var token = "";
        var y = date.getYear() + "";
        var M = date.getMonth() + 1;
        var d = date.getDate();
        var E = date.getDay();
        var H = date.getHours();
        var m = date.getMinutes();
        var s = date.getSeconds();
        var yyyy, yy, MMM, MM, dd, hh, h, mm, ss, ampm, HH, H, KK, K, kk, k;
        // Convert real date parts into formatted versions
        var value = new Object();
        if (y.length < 4) { y = "" + (y - 0 + 1900); }
        value["y"] = "" + y;
        value["yyyy"] = y;
        value["yy"] = y.substring(2, 4);
        value["M"] = M;
        value["MM"] = DateFormat.LZ(M);
        value["MMM"] = DateFormat.MONTH_NAMES[M - 1];
        value["NNN"] = DateFormat.MONTH_NAMES[M + 11];
        value["d"] = d;
        value["dd"] = DateFormat.LZ(d);
        value["E"] = DateFormat.DAY_NAMES[E + 7];
        value["EE"] = DateFormat.DAY_NAMES[E];
        value["H"] = H;
        value["HH"] = DateFormat.LZ(H);
        if (H == 0) { value["h"] = 12; }
        else if (H > 12) { value["h"] = H - 12; }
        else { value["h"] = H; }
        value["hh"] = DateFormat.LZ(value["h"]);
        if (H > 11) { value["K"] = H - 12; } else { value["K"] = H; }
        value["k"] = H + 1;
        value["KK"] = DateFormat.LZ(value["K"]);
        value["kk"] = DateFormat.LZ(value["k"]);
        if (H > 11) { value["a"] = "PM"; }
        else { value["a"] = "AM"; }
        value["m"] = m;
        value["mm"] = DateFormat.LZ(m);
        value["s"] = s;
        value["ss"] = DateFormat.LZ(s);
        while (i_format < format.length) {
            c = format.charAt(i_format);
            token = "";
            while ((format.charAt(i_format) == c) && (i_format < format.length))
                token += format.charAt(i_format++);
            if (value[token] != null) result += value[token];
            else result += token;
        }
        return result;
    },
    _isInteger: function (val) {
        var digits = "1234567890";
        for (var i = 0; i < val.length; i++)
            if (digits.indexOf(val.charAt(i)) == -1) return false;
        return true;
    },
    _getInt: function (str, i, minlength, maxlength) {
        for (var x = maxlength; x >= minlength; x--) {
            var token = str.substring(i, i + x);
            if (token.length < minlength) return null;
            if (DateFormat._isInteger(token)) return token;
        }
        return null;
    },
    parseFormat: function (val, format) {
        val = val + "";
        format = format + "";
        var i_val = 0;
        var i_format = 0;
        var c = "";
        var token = "";
        var token2 = "";
        var x, y;
        var now = new Date();
        var year = now.getYear();
        var month = now.getMonth() + 1;
        var date = 1;
        var hh = now.getHours();
        var mm = now.getMinutes();
        var ss = now.getSeconds();
        var ampm = "";

        while (i_format < format.length) {
            // Get next token from format string
            c = format.charAt(i_format);
            token = "";
            while ((format.charAt(i_format) == c) && (i_format < format.length))
                token += format.charAt(i_format++);
            // Extract contents of value based on format token
            if (token == "yyyy" || token == "yy" || token == "y") {
                if (token == "yyyy") x = 4; y = 4;
                if (token == "yy") x = 2; y = 2;
                if (token == "y") x = 2; y = 4;
                year = DateFormat._getInt(val, i_val, x, y);
                if (year == null) return 0;
                i_val += year.length;
                if (year.length == 2) {
                    if (year > 70) year = 1900 + (year - 0);
                    else year = 2000 + (year - 0);
                }
            } else if (token == "MMM" || token == "NNN") {
                month = 0;
                for (var i = 0; i < DateFormat.MONTH_NAMES.length; i++) {
                    var month_name = DateFormat.MONTH_NAMES[i];
                    if (val.substring(i_val, i_val + month_name.length).toLowerCase() == month_name.toLowerCase()) {
                        if (token == "MMM" || (token == "NNN" && i > 11)) {
                            month = i + 1;
                            if (month > 12) month -= 12;
                            i_val += month_name.length;
                            break;
                        }
                    }
                }
                if ((month < 1) || (month > 12)) return 0;
            } else if (token == "EE" || token == "E") {
                for (var i = 0; i < DateFormat.DAY_NAMES.length; i++) {
                    var day_name = DateFormat.DAY_NAMES[i];
                    if (val.substring(i_val, i_val + day_name.length).toLowerCase() == day_name.toLowerCase()) {
                        i_val += day_name.length;
                        break;
                    }
                }
            } else if (token == "MM" || token == "M") {
                month = DateFormat._getInt(val, i_val, token.length, 2);
                if (month == null || (month < 1) || (month > 12)) return 0;
                i_val += month.length;
            } else if (token == "dd" || token == "d") {
                date = DateFormat._getInt(val, i_val, token.length, 2);
                if (date == null || (date < 1) || (date > 31)) return 0;
                i_val += date.length;
            } else if (token == "hh" || token == "h") {
                hh = DateFormat._getInt(val, i_val, token.length, 2);
                if (hh == null || (hh < 1) || (hh > 12)) return 0;
                i_val += hh.length;
            } else if (token == "HH" || token == "H") {
                hh = DateFormat._getInt(val, i_val, token.length, 2);
                if (hh == null || (hh < 0) || (hh > 23)) return 0;
                i_val += hh.length;
            } else if (token == "KK" || token == "K") {
                hh = DateFormat._getInt(val, i_val, token.length, 2);
                if (hh == null || (hh < 0) || (hh > 11)) return 0;
                i_val += hh.length;
            } else if (token == "kk" || token == "k") {
                hh = DateFormat._getInt(val, i_val, token.length, 2);
                if (hh == null || (hh < 1) || (hh > 24)) return 0;
                i_val += hh.length; hh--;
            } else if (token == "mm" || token == "m") {
                mm = DateFormat._getInt(val, i_val, token.length, 2);
                if (mm == null || (mm < 0) || (mm > 59)) return 0;
                i_val += mm.length;
            } else if (token == "ss" || token == "s") {
                ss = DateFormat._getInt(val, i_val, token.length, 2);
                if (ss == null || (ss < 0) || (ss > 59)) return 0;
                i_val += ss.length;
            } else if (token == "a") {
                if (val.substring(i_val, i_val + 2).toLowerCase() == "am") ampm = "AM";
                else if (val.substring(i_val, i_val + 2).toLowerCase() == "pm") ampm = "PM";
                else return 0;
                i_val += 2;
            } else {
                if (val.substring(i_val, i_val + token.length) != token) return 0;
                else i_val += token.length;
            }
        }
        // If there are any trailing characters left in the value, it doesn't match
        if (i_val != val.length) return 0;
        // Is date valid for month?
        if (month == 2) {
            // Check for leap year
            if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) { // leap year
                if (date > 29) return 0;
            } else if (date > 28) {
                return 0;
            }
        }
        if ((month == 4) || (month == 6) || (month == 9) || (month == 11))
            if (date > 30) return 0;
        // Correct hours value
        if (hh < 12 && ampm == "PM") hh = hh - 0 + 12;
        else if (hh > 11 && ampm == "AM") hh -= 12;
        var newdate = new Date(year, month - 1, date, hh, mm, ss);
        return newdate;
    },
    parse: function (val, format) {
        if (format) {
            return DateFormat.parseFormat(val, format);
        } else {
            var preferEuro = (arguments.length == 2) ? arguments[1] : false;
            var generalFormats = new Array('y-M-d', 'MMM d, y', 'MMM d,y', 'y-MMM-d', 'd-MMM-y', 'MMM d');
            var monthFirst = new Array('M/d/y', 'M-d-y', 'M.d.y', 'MMM-d', 'M/d', 'M-d');
            var dateFirst = new Array('d/M/y', 'd-M-y', 'd.M.y', 'd-MMM', 'd/M', 'd-M');
            var checkList = [generalFormats, preferEuro ? dateFirst : monthFirst, preferEuro ? monthFirst : dateFirst];
            var d = null;
            for (var i = 0; i < checkList.length; i++) {
                var l = checkList[i];
                for (var j = 0; j < l.length; j++) {
                    d = DateFormat.parseFormat(val, l[j]);
                    if (d != 0) return new Date(d);
                }
            }
            return null;
        }
    }
});

DateFormat.prototype = {
    initialize: function (format) { this.format = format; },
    parse: function (value) { return DateFormat.parseFormat(value, this.format); },
    format: function (value) { return DateFormat.format(value, this.format); }
}

Date.prototype.format = function (format) {
    return DateFormat.format(this, format);
}