From: Alan Knowles <alan@akbkhome.com>
Date: Tue, 13 Jul 2010 04:35:59 +0000 (+0800)
Subject: DateExtra.js
X-Git-Url: http://git.roojs.org/?p=gnome.introspection-doc-generator;a=commitdiff_plain;h=b5b15584c1e76914c2ec1a9cc9f75a4ce266d79f

DateExtra.js
---

diff --git a/DateExtra.js b/DateExtra.js
index e69de29..b25bec3 100644
--- a/DateExtra.js
+++ b/DateExtra.js
@@ -0,0 +1,787 @@
+/*
+ * Based on:
+ * Ext JS Library 1.1.1
+ * Copyright(c) 2006-2007, Ext JS, LLC.
+ *
+ * Originally Released Under LGPL - original licence link has changed is not relivant.
+ *
+ * Fork - LGPL
+ * <script type="text/javascript">
+ */
+// usage: Date=  imports.Date.Date;
+
+
+String          = imports.String.String;
+XObject         = imports.XObject.XObject;
+
+
+/**
+ * @class Date
+ *
+ * The date parsing and format syntax is a subset of
+ * <a href="http://www.php.net/date">PHP's date() function</a>, and the formats that are
+ * supported will provide results equivalent to their PHP versions.
+ *
+ * Following is the list of all currently supported formats:
+ *<pre>
+Sample date:
+'Wed Jan 10 2007 15:05:01 GMT-0600 (Central Standard Time)'
+
+Format  Output      Description
+------  ----------  --------------------------------------------------------------
+  d      10         Day of the month, 2 digits with leading zeros
+  D      Wed        A textual representation of a day, three letters
+  j      10         Day of the month without leading zeros
+  l      Wednesday  A full textual representation of the day of the week
+  S      th         English ordinal day of month suffix, 2 chars (use with j)
+  w      3          Numeric representation of the day of the week
+  z      9          The julian date, or day of the year (0-365)
+  W      01         ISO-8601 2-digit week number of year, weeks starting on Monday (00-52)
+  F      January    A full textual representation of the month
+  m      01         Numeric representation of a month, with leading zeros
+  M      Jan        Month name abbreviation, three letters
+  n      1          Numeric representation of a month, without leading zeros
+  t      31         Number of days in the given month
+  L      0          Whether it's a leap year (1 if it is a leap year, else 0)
+  Y      2007       A full numeric representation of a year, 4 digits
+  y      07         A two digit representation of a year
+  a      pm         Lowercase Ante meridiem and Post meridiem
+  A      PM         Uppercase Ante meridiem and Post meridiem
+  g      3          12-hour format of an hour without leading zeros
+  G      15         24-hour format of an hour without leading zeros
+  h      03         12-hour format of an hour with leading zeros
+  H      15         24-hour format of an hour with leading zeros
+  i      05         Minutes with leading zeros
+  s      01         Seconds, with leading zeros
+  O      -0600      Difference to Greenwich time (GMT) in hours
+  T      CST        Timezone setting of the machine running the code
+  Z      -21600     Timezone offset in seconds (negative if west of UTC, positive if east)
+</pre>
+ *
+ * Example usage (note that you must escape format specifiers with '\\' to render them as character literals):
+ * <pre><code>
+var dt = new Date('1/10/2007 03:05:01 PM GMT-0600');
+document.write(dt.format('Y-m-d'));                         //2007-01-10
+document.write(dt.format('F j, Y, g:i a'));                 //January 10, 2007, 3:05 pm
+document.write(dt.format('l, \\t\\he dS of F Y h:i:s A'));  //Wednesday, the 10th of January 2007 03:05:01 PM
+ </code></pre>
+ *
+ * Here are some standard date/time patterns that you might find helpful.  They
+ * are not part of the source of Date.js, but to use them you can simply copy this
+ * block of code into any script that is included after Date.js and they will also become
+ * globally available on the Date object.  Feel free to add or remove patterns as needed in your code.
+ * <pre><code>
+Date.patterns = {
+    ISO8601Long:"Y-m-d H:i:s",
+    ISO8601Short:"Y-m-d",
+    ShortDate: "n/j/Y",
+    LongDate: "l, F d, Y",
+    FullDateTime: "l, F d, Y g:i:s A",
+    MonthDay: "F d",
+    ShortTime: "g:i A",
+    LongTime: "g:i:s A",
+    SortableDateTime: "Y-m-d\\TH:i:s",
+    UniversalSortableDateTime: "Y-m-d H:i:sO",
+    YearMonth: "F, Y"
+};
+</code></pre>
+ *
+ * Example usage:
+ * <pre><code>
+var dt = new Date();
+document.write(dt.format(Date.patterns.ShortDate));
+ </code></pre>
+ */
+
+/*
+ * Most of the date-formatting functions below are the excellent work of Baron Schwartz.
+ * They generate precompiled functions from date formats instead of parsing and
+ * processing the pattern every time you format a date.  These functions are available
+ * on every Date object (any javascript function).
+ *
+ * The original article and download are here:
+ * http://www.xaprb.com/blog/2005/12/12/javascript-closures-for-runtime-efficiency/
+ *
+ */
+ 
+     
+     // was in core
+    /**
+     Returns the number of milliseconds between this date and date
+     @param {Date} date (optional) Defaults to now
+     @return {Number} The diff in milliseconds
+     @member Date getElapsed
+     */
+DateExtra = Date; 
+XObject.extend(Date,
+    {
+        
+        // private
+        parseFunctions : {count:0},
+        // private
+        parseRegexes : [],
+        // private
+        formatFunctions : {count:0},
+            
+            
+        // private
+        // safari setMonth is broken
+         
+        /** Date interval constant 
+        * @static 
+        * @type String */
+        MILLI : "ms",
+        /** Date interval constant 
+        * @static 
+        * @type String */
+        SECOND : "s",
+        /** Date interval constant 
+        * @static 
+        * @type String */
+        MINUTE : "mi",
+        /** Date interval constant 
+        * @static 
+        * @type String */
+        HOUR : "h",
+        /** Date interval constant 
+        * @static 
+        * @type String */
+        DAY : "d",
+        /** Date interval constant 
+        * @static 
+        * @type String */
+        MONTH : "mo",
+        /** Date interval constant 
+        * @static 
+        * @type String */
+        YEAR : "y",
+
+        // private
+        daysInMonth : [31,28,31,30,31,30,31,31,30,31,30,31],
+
+        /**
+         * An array of textual month names.
+         * Override these values for international dates, for example...
+         * Date.monthNames = ['JanInYourLang', 'FebInYourLang', ...];
+         * @type Array
+         * @static
+         */
+        monthNames : [
+            "January",
+            "February",
+            "March",
+            "April",
+            "May",
+            "June",
+            "July",
+            "August",
+            "September",
+            "October",
+            "November",
+            "December"],
+
+        /**
+         * An array of textual day names.
+         * Override these values for international dates, for example...
+         * Date.dayNames = ['SundayInYourLang', 'MondayInYourLang', ...];
+         * @type Array
+         * @static
+         */
+        dayNames : [
+            "Sunday",
+            "Monday",
+            "Tuesday",
+            "Wednesday",
+            "Thursday",
+            "Friday",
+            "Saturday"],
+
+        // private
+        y2kYear : 50,
+        // private
+        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},
+        
+        createNewFormat : function(format) {
+            var funcName = "format" + Date.formatFunctions.count++;
+            Date.formatFunctions[format] = funcName;
+            var code = "Date.prototype." + funcName + " = function(){return ";
+            var special = false;
+            var ch = '';
+            for (var 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(ch);
+                }
+            }
+            /** eval:var:zzzzzzzzzzzzz */
+            eval(code.substring(0, code.length - 3) + ";}");
+        },
+
+        // private
+        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) + "' + ";
+            }
+        },
+
+        /**
+         * Parses the passed string using the specified format. Note that this function expects dates in normal calendar
+         * format, meaning that months are 1-based (1 = January) and not zero-based like in JavaScript dates.  Any part of
+         * the date format that is not specified will default to the current date value for that part.  Time parts can also
+         * be specified, but default to 0.  Keep in mind that the input date string must precisely match the specified format
+         * string or the parse operation will fail.
+         * Example Usage:
+        <pre><code>
+        //dt = Fri May 25 2007 (current date)
+        var dt = new Date();
+
+        //dt = Thu May 25 2006 (today's month/day in 2006)
+        dt = Date.parseDate("2006", "Y");
+
+        //dt = Sun Jan 15 2006 (all date parts specified)
+        dt = Date.parseDate("2006-1-15", "Y-m-d");
+
+        //dt = Sun Jan 15 2006 15:20:01 GMT-0600 (CST)
+        dt = Date.parseDate("2006-1-15 3:20:01 PM", "Y-m-d h:i:s A" );
+        </code></pre>
+         * @param {String} input The unparsed date as a string
+         * @param {String} format The format the date is in
+         * @return {Date} The parsed date
+         * @static
+         */
+        parseDate : function(input, format) {
+            if (Date.parseFunctions[format] == null) {
+                Date.createParser(format);
+            }
+            var func = Date.parseFunctions[format];
+            return Date[func](input);
+        },
+
+        // private
+        createParser : function(format) {
+            var funcName = "parse" + Date.parseFunctions.count++;
+            var regexNum = Date.parseRegexes.length;
+            var currentGroup = 1;
+            Date.parseFunctions[format] = funcName;
+
+            var code = "Date." + funcName + " = function(input){\n"
+                + "var y = -1, m = -1, d = -1, h = -1, i = -1, s = -1, o, z, v;\n"
+                + "var d = new Date();\n"
+                + "y = d.getFullYear();\n"
+                + "m = d.getMonth();\n"
+                + "d = d.getDate();\n"
+                + "var results = input.match(Date.parseRegexes[" + regexNum + "]);\n"
+                + "if (results && results.length > 0) {";
+            var regex = "";
+
+            var special = false;
+            var ch = '';
+            for (var i = 0; i < format.length; ++i) {
+                ch = format.charAt(i);
+                if (!special && ch == "\\") {
+                    special = true;
+                }
+                else if (special) {
+                    special = false;
+                    regex += String.escape(ch);
+                }
+                else {
+                    var obj = Date.formatCodeToRegex(ch, currentGroup);
+                    currentGroup += obj.g;
+                    regex += obj.s;
+                    if (obj.g && obj.c) {
+                        code += obj.c;
+                    }
+                }
+            }
+
+            code += "if (y >= 0 && m >= 0 && d > 0 && h >= 0 && i >= 0 && s >= 0)\n"
+                + "{v = new Date(y, m, d, h, i, s);}\n"
+                + "else if (y >= 0 && m >= 0 && d > 0 && h >= 0 && i >= 0)\n"
+                + "{v = new Date(y, m, d, h, i);}\n"
+                + "else if (y >= 0 && m >= 0 && d > 0 && h >= 0)\n"
+                + "{v = new Date(y, m, d, h);}\n"
+                + "else if (y >= 0 && m >= 0 && d > 0)\n"
+                + "{v = new Date(y, m, d);}\n"
+                + "else if (y >= 0 && m >= 0)\n"
+                + "{v = new Date(y, m);}\n"
+                + "else if (y >= 0)\n"
+                + "{v = new Date(y);}\n"
+                + "}return (v && (z || o))?\n" // favour UTC offset over GMT offset
+                + "    ((z)? v.add(Date.SECOND, (v.getTimezoneOffset() * 60) + (z*1)) :\n" // reset to UTC, then add offset
+                + "        v.add(Date.HOUR, (v.getGMTOffset() / 100) + (o / -100))) : v\n" // reset to GMT, then add offset
+                + ";}";
+
+            Date.parseRegexes[regexNum] = new RegExp("^" + regex + "$");
+             /** eval:var:zzzzzzzzzzzzz */
+            eval(code);
+        },
+
+        // private
+        formatCodeToRegex : function(character, currentGroup) {
+            switch (character) {
+            case "D":
+                return {g:0,
+                c:null,
+                s:"(?:Sun|Mon|Tue|Wed|Thu|Fri|Sat)"};
+            case "j":
+                return {g:1,
+                    c:"d = parseInt(results[" + currentGroup + "], 10);\n",
+                    s:"(\\d{1,2})"}; // day of month without leading zeroes
+            case "d":
+                return {g:1,
+                    c:"d = parseInt(results[" + currentGroup + "], 10);\n",
+                    s:"(\\d{2})"}; // day of month with leading zeroes
+            case "l":
+                return {g:0,
+                    c:null,
+                    s:"(?:" + Date.dayNames.join("|") + ")"};
+            case "S":
+                return {g:0,
+                    c:null,
+                    s:"(?:st|nd|rd|th)"};
+            case "w":
+                return {g:0,
+                    c:null,
+                    s:"\\d"};
+            case "z":
+                return {g:0,
+                    c:null,
+                    s:"(?:\\d{1,3})"};
+            case "W":
+                return {g:0,
+                    c:null,
+                    s:"(?:\\d{2})"};
+            case "F":
+                return {g:1,
+                    c:"m = parseInt(Date.monthNumbers[results[" + currentGroup + "].substring(0, 3)], 10);\n",
+                    s:"(" + Date.monthNames.join("|") + ")"};
+            case "M":
+                return {g:1,
+                    c:"m = parseInt(Date.monthNumbers[results[" + currentGroup + "]], 10);\n",
+                    s:"(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)"};
+            case "n":
+                return {g:1,
+                    c:"m = parseInt(results[" + currentGroup + "], 10) - 1;\n",
+                    s:"(\\d{1,2})"}; // Numeric representation of a month, without leading zeros
+            case "m":
+                return {g:1,
+                    c:"m = parseInt(results[" + currentGroup + "], 10) - 1;\n",
+                    s:"(\\d{2})"}; // Numeric representation of a month, with leading zeros
+            case "t":
+                return {g:0,
+                    c:null,
+                    s:"\\d{1,2}"};
+            case "L":
+                return {g:0,
+                    c:null,
+                    s:"(?:1|0)"};
+            case "Y":
+                return {g:1,
+                    c:"y = parseInt(results[" + currentGroup + "], 10);\n",
+                    s:"(\\d{4})"};
+            case "y":
+                return {g:1,
+                    c:"var ty = parseInt(results[" + currentGroup + "], 10);\n"
+                        + "y = ty > Date.y2kYear ? 1900 + ty : 2000 + ty;\n",
+                    s:"(\\d{1,2})"};
+            case "a":
+                return {g:1,
+                    c:"if (results[" + currentGroup + "] == 'am') {\n"
+                        + "if (h == 12) { h = 0; }\n"
+                        + "} else { if (h < 12) { h += 12; }}",
+                    s:"(am|pm)"};
+            case "A":
+                return {g:1,
+                    c:"if (results[" + currentGroup + "] == 'AM') {\n"
+                        + "if (h == 12) { h = 0; }\n"
+                        + "} else { if (h < 12) { h += 12; }}",
+                    s:"(AM|PM)"};
+            case "g":
+            case "G":
+                return {g:1,
+                    c:"h = parseInt(results[" + currentGroup + "], 10);\n",
+                    s:"(\\d{1,2})"}; // 12/24-hr format  format of an hour without leading zeroes
+            case "h":
+            case "H":
+                return {g:1,
+                    c:"h = parseInt(results[" + currentGroup + "], 10);\n",
+                    s:"(\\d{2})"}; //  12/24-hr format  format of an hour with leading zeroes
+            case "i":
+                return {g:1,
+                    c:"i = parseInt(results[" + currentGroup + "], 10);\n",
+                    s:"(\\d{2})"};
+            case "s":
+                return {g:1,
+                    c:"s = parseInt(results[" + currentGroup + "], 10);\n",
+                    s:"(\\d{2})"};
+            case "O":
+                return {g:1,
+                    c:[
+                        "o = results[", currentGroup, "];\n",
+                        "var sn = o.substring(0,1);\n", // get + / - sign
+                        "var hr = o.substring(1,3)*1 + Math.floor(o.substring(3,5) / 60);\n", // get hours (performs minutes-to-hour conversion also)
+                        "var mn = o.substring(3,5) % 60;\n", // get minutes
+                        "o = ((-12 <= (hr*60 + mn)/60) && ((hr*60 + mn)/60 <= 14))?\n", // -12hrs <= GMT offset <= 14hrs
+                        "    (sn + String.leftPad(hr, 2, 0) + String.leftPad(mn, 2, 0)) : null;\n"
+                    ].join(""),
+                    s:"([+\-]\\d{4})"};
+            case "T":
+                return {g:0,
+                    c:null,
+                    s:"[A-Z]{1,4}"}; // timezone abbrev. may be between 1 - 4 chars
+            case "Z":
+                return {g:1,
+                    c:"z = results[" + currentGroup + "];\n" // -43200 <= UTC offset <= 50400
+                          + "z = (-43200 <= z*1 && z*1 <= 50400)? z : null;\n",
+                    s:"([+\-]?\\d{1,5})"}; // leading '+' sign is optional for UTC offset
+            default:
+            
+                return {g:0,
+                    c:null,
+                    s:String.escape(character)};
+            }
+        }
+
+        
+    
+}); // end static date..
+DateExtra.prototype = DateExtra
+// now add functions to date..
+XObject.extend(Date.prototype,
+    {
+
+        getElapsed : function(date) {
+            return Math.abs((date || new Date()).getTime()-this.getTime());
+        },
+         
+
+        /**
+         * Formats a date given the supplied format string
+         * @param {String} format The format string
+         * @return {String} The formatted date
+         * @method
+         */
+
+        
+        format : function(format) {
+            if (Date.formatFunctions[format] == null) {
+                Date.createNewFormat(format);
+            }
+            var func = Date.formatFunctions[format];
+            return this[func]();
+        },
+
+        // private - why is dataFormat an alias?
+        //format : dateFormat;
+
+        // private
+
+        /**
+         * Get the timezone abbreviation of the current date (equivalent to the format specifier 'T').
+         * @return {String} The abbreviated timezone name (e.g. 'CST')
+         */
+        getTimezone : function() {
+            return this.toString().replace(/^.*? ([A-Z]{1,4})[\-+][0-9]{4} .*$/, "$1");
+        },
+
+        /**
+         * Get the offset from GMT of the current date (equivalent to the format specifier 'O').
+         * @return {String} The 4-character offset string prefixed with + or - (e.g. '-0600')
+         */
+        getGMTOffset : function() {
+            return (this.getTimezoneOffset() > 0 ? "-" : "+")
+                + String.leftPad(Math.abs(Math.floor(this.getTimezoneOffset() / 60)), 2, "0")
+                + String.leftPad(this.getTimezoneOffset() % 60, 2, "0");
+        },
+
+        /**
+         * Get the numeric day number of the year, adjusted for leap year.
+         * @return {Number} 0 through 364 (365 in leap years)
+         */
+        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;
+        },
+
+        /**
+         * Get the string representation of the numeric week number of the year
+         * (equivalent to the format specifier 'W').
+         * @return {String} '00' through '52'
+         */
+        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);
+            return String.leftPad(((now - then) / 7) + 1, 2, "0");
+        },
+
+        /**
+         * Whether or not the current date is in a leap year.
+         * @return {Boolean} True if the current date is in a leap year, else false
+         */
+        isLeapYear : function() {
+            var year = this.getFullYear();
+            return ((year & 3) == 0 && (year % 100 || (year % 400 == 0 && year)));
+        },
+
+        /**
+         * Get the first day of the current month, adjusted for leap year.  The returned value
+         * is the numeric day index within the week (0-6) which can be used in conjunction with
+         * the {@link #monthNames} array to retrieve the textual day name.
+         * Example:
+         *<pre><code>
+        var dt = new Date('1/10/2007');
+        document.write(Date.dayNames[dt.getFirstDayOfMonth()]); //output: 'Monday'
+        </code></pre>
+         * @return {Number} The day number (0-6)
+         */
+        getFirstDayOfMonth : function() {
+            var day = (this.getDay() - (this.getDate() - 1)) % 7;
+            return (day < 0) ? (day + 7) : day;
+        },
+
+        /**
+         * Get the last day of the current month, adjusted for leap year.  The returned value
+         * is the numeric day index within the week (0-6) which can be used in conjunction with
+         * the {@link #monthNames} array to retrieve the textual day name.
+         * Example:
+         *<pre><code>
+        var dt = new Date('1/10/2007');
+        document.write(Date.dayNames[dt.getLastDayOfMonth()]); //output: 'Wednesday'
+        </code></pre>
+         * @return {Number} The day number (0-6)
+         */
+        getLastDayOfMonth : function() {
+            var day = (this.getDay() + (Date.daysInMonth[this.getMonth()] - this.getDate())) % 7;
+            return (day < 0) ? (day + 7) : day;
+        },
+
+
+        /**
+         * Get the first date of this date's month
+         * @return {Date}
+         */
+        getFirstDateOfMonth : function() {
+            return new Date(this.getFullYear(), this.getMonth(), 1);
+        },
+
+        /**
+         * Get the last date of this date's month
+         * @return {Date}
+         */
+        getLastDateOfMonth : function() {
+            return new Date(this.getFullYear(), this.getMonth(), this.getDaysInMonth());
+        },
+        /**
+         * Get the number of days in the current month, adjusted for leap year.
+         * @return {Number} The number of days in the month
+         */
+        getDaysInMonth : function() {
+            Date.daysInMonth[1] = this.isLeapYear() ? 29 : 28;
+            return Date.daysInMonth[this.getMonth()];
+        },
+
+        /**
+         * Get the English ordinal suffix of the current day (equivalent to the format specifier 'S').
+         * @return {String} 'st, 'nd', 'rd' or 'th'
+         */
+        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";
+            }
+        },
+
+
+        /**
+         * Creates and returns a new Date instance with the exact same date value as the called instance.
+         * Dates are copied and passed by reference, so if a copied date variable is modified later, the original
+         * variable will also be changed.  When the intention is to create a new variable that will not
+         * modify the original instance, you should create a clone.
+         *
+         * Example of correctly cloning a date:
+         * <pre><code>
+        //wrong way:
+        var orig = new Date('10/1/2006');
+        var copy = orig;
+        copy.setDate(5);
+        document.write(orig);  //returns 'Thu Oct 05 2006'!
+
+        //correct way:
+        var orig = new Date('10/1/2006');
+        var copy = orig.clone();
+        copy.setDate(5);
+        document.write(orig);  //returns 'Thu Oct 01 2006'
+        </code></pre>
+         * @return {Date} The new Date instance
+         */
+        clone : function() {
+            return new Date(this.getTime());
+        },
+
+        /**
+         * Clears any time information from this date
+         @param {Boolean} clone true to create a clone of this date, clear the time and return it
+         @return {Date} this or the clone
+         */
+        clearTime : function(clone){
+            if(clone){
+                return this.clone().clearTime();
+            }
+            this.setHours(0);
+            this.setMinutes(0);
+            this.setSeconds(0);
+            this.setMilliseconds(0);
+            return this;
+        },
+
+        /**
+         * Provides a convenient method of performing basic date arithmetic.  This method
+         * does not modify the Date instance being called - it creates and returns
+         * a new Date instance containing the resulting date value.
+         *
+         * Examples:
+         * <pre><code>
+        //Basic usage:
+        var dt = new Date('10/29/2006').add(Date.DAY, 5);
+        document.write(dt); //returns 'Fri Oct 06 2006 00:00:00'
+
+        //Negative values will subtract correctly:
+        var dt2 = new Date('10/1/2006').add(Date.DAY, -5);
+        document.write(dt2); //returns 'Tue Sep 26 2006 00:00:00'
+
+        //You can even chain several calls together in one line!
+        var dt3 = new Date('10/1/2006').add(Date.DAY, 5).add(Date.HOUR, 8).add(Date.MINUTE, -30);
+        document.write(dt3); //returns 'Fri Oct 06 2006 07:30:00'
+         </code></pre>
+         *
+         * @param {String} interval   A valid date interval enum value
+         * @param {Number} value      The amount to add to the current date
+         * @return {Date} The new Date instance
+         */
+        add : function(interval, value){
+          var d = this.clone();
+          if (!interval || value === 0) return d;
+          switch(interval.toLowerCase()){
+            case Date.MILLI:
+              d.setMilliseconds(this.getMilliseconds() + value);
+              break;
+            case Date.SECOND:
+              d.setSeconds(this.getSeconds() + value);
+              break;
+            case Date.MINUTE:
+              d.setMinutes(this.getMinutes() + value);
+              break;
+            case Date.HOUR:
+              d.setHours(this.getHours() + value);
+              break;
+            case Date.DAY:
+              d.setDate(this.getDate() + value);
+              break;
+            case Date.MONTH:
+              var day = this.getDate();
+              if(day > 28){
+                  day = Math.min(day, this.getFirstDateOfMonth().add('mo', value).getLastDateOfMonth().getDate());
+              }
+              d.setDate(day);
+              d.setMonth(this.getMonth() + value);
+              break;
+            case Date.YEAR:
+              d.setFullYear(this.getFullYear() + value);
+              break;
+          }
+          return d;
+        }
+
+});
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