Re-written date functions to not use eval()

data-functions.js

/*
 * Copyright (C) 2004 Baron Schwartz <baron at sequent dot org>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by the
 * Free Software Foundation, version 2.1.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
 * details.
 */

Date.parseFunctions = {count: 0};
Date.parseRegexes = [];
Date.formatFunctions = {count: 0};

Date.prototype.dateFormat = function (format) {
    return Date.createNewFormat.call(this, format);
};

Date.createNewFormat = function (format) {
    var funcName = "format" + Date.formatFunctions.count++,
        code = "",
        special = false,
        ch = '',
        i = 0;
    
    Date.formatFunctions[format] = funcName;
    
    for (i = 0; i < format.length; ++i) {
        ch = format.charAt(i);
        if (!special && ch === "\\") {
            special = true;
        } else if (special) {
            special = false;
            code += String.escape(ch);
        } else {
            code += Date.getFormatCode.call(this, ch);
        }
    }
    return code;
};

Date.getFormatCode = function (character) {
    switch (character) {
    case "d":
        return String.leftPad(this.getDate(), 2, '0');
    case "D":
        return Date.dayNames[this.getDay()].substring(0, 3);
    case "j":
        return this.getDate();
    case "l":
        return Date.dayNames[this.getDay()];
    case "S":
        return this.getSuffix();
    case "w":
        return this.getDay();
    case "z":
        return this.getDayOfYear();
    case "W":
        return this.getWeekOfYear();
    case "F":
        return Date.monthNames[this.getMonth()];
    case "m":
        return String.leftPad(this.getMonth() + 1, 2, '0');
    case "M":
        return Date.monthNames[this.getMonth()].substring(0, 3);
    case "n":
        return (this.getMonth() + 1);
    case "t":
        return this.getDaysInMonth();
    case "L":
        return (this.isLeapYear() ? 1 : 0);
    case "Y":
        return this.getFullYear();
    case "y":
        return ('' + this.getFullYear()).substring(2, 4);
    case "a":
        return (this.getHours() < 12 ? 'am' : 'pm');
    case "A":
        return (this.getHours() < 12 ? 'AM' : 'PM');
    case "g":
        return ((this.getHours() % 12) ? this.getHours() % 12 : 12);
    case "G":
        return this.getHours();
    case "h":
        return String.leftPad((this.getHours() % 12) ? this.getHours() % 12 : 12, 2, '0');
    case "H":
        return String.leftPad(this.getHours(), 2, '0');
    case "i":
        return String.leftPad(this.getMinutes(), 2, '0');
    case "s":
        return String.leftPad(this.getSeconds(), 2, '0');
    case "O":
        return this.getGMTOffset();
    case "T":
        return this.getTimezone();
    case "Z":
        return (this.getTimezoneOffset() * -60);
    default:
        return String.escape(character);
    }
};

Date.parseDate = function (input, format) {
    return new Date(input);
};

Date.prototype.getTimezone = function() {
    return this.toString().replace(
        /^.*? ([A-Z]{3}) [0-9]{4}.*$/, "$1").replace(
        /^.*?\(([A-Z])[a-z]+ ([A-Z])[a-z]+ ([A-Z])[a-z]+\)$/, "$1$2$3");
}

Date.prototype.getGMTOffset = function() {
    return (this.getTimezoneOffset() > 0 ? "-" : "+")
        + String.leftPad(Math.floor(this.getTimezoneOffset() / 60), 2, "0")
        + String.leftPad(this.getTimezoneOffset() % 60, 2, "0");
}

Date.prototype.getDayOfYear = function() {
    var num = 0;
    Date.daysInMonth[1] = this.isLeapYear() ? 29 : 28;
    for (var i = 0; i < this.getMonth(); ++i) {
        num += Date.daysInMonth[i];
    }
    return num + this.getDate() - 1;
}

Date.prototype.getWeekOfYear = function() {
    // Skip to Thursday of this week
    var now = this.getDayOfYear() + (4 - this.getDay());
    // Find the first Thursday of the year
    var jan1 = new Date(this.getFullYear(), 0, 1);
    var then = (7 - jan1.getDay() + 4);
    document.write(then);
    return String.leftPad(((now - then) / 7) + 1, 2, "0");
}

Date.prototype.isLeapYear = function() {
    var year = this.getFullYear();
    return ((year & 3) == 0 && (year % 100 || (year % 400 == 0 && year)));
}

Date.prototype.getFirstDayOfMonth = function() {
    var day = (this.getDay() - (this.getDate() - 1)) % 7;
    return (day < 0) ? (day + 7) : day;
}

Date.prototype.getLastDayOfMonth = function() {
    var day = (this.getDay() + (Date.daysInMonth[this.getMonth()] - this.getDate())) % 7;
    return (day < 0) ? (day + 7) : day;
}

Date.prototype.getDaysInMonth = function() {
    Date.daysInMonth[1] = this.isLeapYear() ? 29 : 28;
    return Date.daysInMonth[this.getMonth()];
}

Date.prototype.getSuffix = function() {
    switch (this.getDate()) {
        case 1:
        case 21:
        case 31:
            return "st";
        case 2:
        case 22:
            return "nd";
        case 3:
        case 23:
            return "rd";
        default:
            return "th";
    }
}

String.escape = function(string) {
    return string.replace(/('|\\)/g, "\\$1");
}

String.leftPad = function (val, size, ch) {
    var result = new String(val);
    if (ch == null) {
        ch = " ";
    }
    while (result.length < size) {
        result = ch + result;
    }
    return result;
}

Date.daysInMonth = [31,28,31,30,31,30,31,31,30,31,30,31];
Date.monthNames =
   ["January",
    "February",
    "March",
    "April",
    "May",
    "June",
    "July",
    "August",
    "September",
    "October",
    "November",
    "December"];
Date.dayNames =
   ["Sunday",
    "Monday",
    "Tuesday",
    "Wednesday",
    "Thursday",
    "Friday",
    "Saturday"];
Date.y2kYear = 50;
Date.monthNumbers = {
    Jan:0,
    Feb:1,
    Mar:2,
    Apr:3,
    May:4,
    Jun:5,
    Jul:6,
    Aug:7,
    Sep:8,
    Oct:9,
    Nov:10,
    Dec:11};
Date.patterns = {
    ISO8601LongPattern:"Y-m-d H:i:s",
    ISO8601ShortPattern:"Y-m-d",
    ShortDatePattern: "n/j/Y",
    LongDatePattern: "l, F d, Y",
    FullDateTimePattern: "l, F d, Y g:i:s A",
    MonthDayPattern: "F d",
    ShortTimePattern: "g:i A",
    LongTimePattern: "g:i:s A",
    SortableDateTimePattern: "Y-m-d\\TH:i:s",
    UniversalSortableDateTimePattern: "Y-m-d H:i:sO",
    YearMonthPattern: "F, Y"};