    // @tag foundation,core
    // @require Object.js
    // @define Ext.Date

    /**
     * @class Ext.Date
     * A set of useful static methods to deal with date
     * Note that if Ext.Date is required and loaded, it will copy all methods / properties to
     * this object for convenience
     *
     * The date parsing and formatting syntax contains a subset of
     * [PHP's `date()` function](http://www.php.net/date), and the formats that are
     * supported will provide results equivalent to their PHP versions.
     *
     * The following is a list of all currently supported formats:
     * <pre class="">
    Format      Description                                                               Example returned values
    ------      -----------------------------------------------------------------------   -----------------------
      d         Day of the month, 2 digits with leading zeros                             01 to 31
      D         A short textual representation of the day of the week                     Mon to Sun
      j         Day of the month without leading zeros                                    1 to 31
      l         A full textual representation of the day of the week                      Sunday to Saturday
      N         ISO-8601 numeric representation of the day of the week                    1 (for Monday) through 7 (for Sunday)
      S         English ordinal suffix for the day of the month, 2 characters             st, nd, rd or th. Works well with j
      w         Numeric representation of the day of the week                             0 (for Sunday) to 6 (for Saturday)
      z         The day of the year (starting from 0)                                     0 to 364 (365 in leap years)
      W         ISO-8601 week number of year, weeks starting on Monday                    01 to 53
      F         A full textual representation of a month, such as January or March        January to December
      m         Numeric representation of a month, with leading zeros                     01 to 12
      M         A short textual representation of a month                                 Jan to Dec
      n         Numeric representation of a month, without leading zeros                  1 to 12
      t         Number of days in the given month                                         28 to 31
      L         Whether it&#39;s a leap year                                                  1 if it is a leap year, 0 otherwise.
      o         ISO-8601 year number (identical to (Y), but if the ISO week number (W)    Examples: 1998 or 2004
                belongs to the previous or next year, that year is used instead)
      Y         A full numeric representation of a year, 4 digits                         Examples: 1999 or 2003
      y         A two digit representation of a year                                      Examples: 99 or 03
      a         Lowercase Ante meridiem and Post meridiem                                 am or pm
      A         Uppercase Ante meridiem and Post meridiem                                 AM or PM
      g         12-hour format of an hour without leading zeros                           1 to 12
      G         24-hour format of an hour without leading zeros                           0 to 23
      h         12-hour format of an hour with leading zeros                              01 to 12
      H         24-hour format of an hour with leading zeros                              00 to 23
      i         Minutes, with leading zeros                                               00 to 59
      s         Seconds, with leading zeros                                               00 to 59
      u         Decimal fraction of a second                                              Examples:
                (minimum 1 digit, arbitrary number of digits allowed)                     001 (i.e. 0.001s) or
                                                                                          100 (i.e. 0.100s) or
                                                                                          999 (i.e. 0.999s) or
                                                                                          999876543210 (i.e. 0.999876543210s)
      O         Difference to Greenwich time (GMT) in hours and minutes                   Example: +1030
      P         Difference to Greenwich time (GMT) with colon between hours and minutes   Example: -08:00
      T         Timezone abbreviation of the machine running the code                     Examples: EST, MDT, PDT ...
      Z         Timezone offset in seconds (negative if west of UTC, positive if east)    -43200 to 50400
      c         ISO 8601 date
                Notes:                                                                    Examples:
                1) If unspecified, the month / day defaults to the current month / day,   1991 or
                   the time defaults to midnight, while the timezone defaults to the      1992-10 or
                   browser's timezone. If a time is specified, it must include both hours 1993-09-20 or
                   and minutes. The "T" delimiter, seconds, milliseconds and timezone     1994-08-19T16:20+01:00 or
                   are optional.                                                          1995-07-18T17:21:28-02:00 or
                2) The decimal fraction of a second, if specified, must contain at        1996-06-17T18:22:29.98765+03:00 or
                   least 1 digit (there is no limit to the maximum number                 1997-05-16T19:23:30,12345-0400 or
                   of digits allowed), and may be delimited by either a '.' or a ','      1998-04-15T20:24:31.2468Z or
                Refer to the examples on the right for the various levels of              1999-03-14T20:24:32Z or
                date-time granularity which are supported, or see                         2000-02-13T21:25:33
                http://www.w3.org/TR/NOTE-datetime for more info.                         2001-01-12 22:26:34
      U         Seconds since the Unix Epoch (January 1 1970 00:00:00 GMT)                1193432466 or -2138434463
      MS        Microsoft AJAX serialized dates                                           \/Date(1238606590509)\/ (i.e. UTC milliseconds since epoch) or
                                                                                          \/Date(1238606590509+0800)\/
      time      A javascript millisecond timestamp                                        1350024476440
      timestamp A UNIX timestamp (same as U)                                              1350024866
    </pre>
     *
     * Example usage (note that you must escape format specifiers with '\\' to render them as character literals):
     *
     *     // Sample date:
     *     // 'Wed Jan 10 2007 15:05:01 GMT-0600 (Central Standard Time)'
     *
     *     var dt = new Date('1/10/2007 03:05:01 PM GMT-0600');
     *     console.log(Ext.Date.format(dt, 'Y-m-d'));                          // 2007-01-10
     *     console.log(Ext.Date.format(dt, 'F j, Y, g:i a'));                  // January 10, 2007, 3:05 pm
     *     console.log(Ext.Date.format(dt, 'l, \\t\\he jS \\of F Y h:i:s A')); // Wednesday, the 10th of January 2007 03:05:01 PM
     *
     * Here are some standard date/time patterns that you might find helpful.  They
     * are not part of the source of Ext.Date, but to use them you can simply copy this
     * block of code into any script that is included after Ext.Date and they will also become
     * globally available on the Date object.  Feel free to add or remove patterns as needed in your code.
     *
     *     Ext.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"
     *     };
     *
     * Example usage:
     *
     *     var dt = new Date();
     *     console.log(Ext.Date.format(dt, Ext.Date.patterns.ShortDate));
     *
     * Developer-written, custom formats may be used by supplying both a formatting and a parsing function
     * which perform to specialized requirements. The functions are stored in {@link #parseFunctions} and {@link #formatFunctions}.
     * @singleton
     */

    /*
     * Most of the date-formatting functions below are the excellent work of Baron Schwartz.
     * (see http://www.xaprb.com/blog/2005/12/12/javascript-closures-for-runtime-efficiency/)
     * They generate precompiled functions from format patterns instead of parsing and
     * processing each pattern every time a date is formatted. These functions are available
     * on every Date object.
     */

    Ext.Date = new function() {
      var utilDate = this,
          stripEscapeRe = /(\\.)/g,
          hourInfoRe = /([gGhHisucUOPZ]|MS)/,
          dateInfoRe = /([djzmnYycU]|MS)/,
          slashRe = /\\/gi,
          numberTokenRe = /\{(\d+)\}/g,
          MSFormatRe = new RegExp('\\/Date\\(([-+])?(\\d+)(?:[+-]\\d{4})?\\)\\/'),
          code = [
            // date calculations (note: the code below creates a dependency on Ext.Number.from())
            "var me = this, dt, y, m, d, h, i, s, ms, o, O, z, zz, u, v, W, year, jan4, week1monday, daysInMonth, dayMatched,",
                "def = me.defaults,",
                "from = Ext.Number.from,",
                "results = String(input).match(me.parseRegexes[{0}]);", // either null, or an array of matched strings

            "if(results){",
                "{1}",

                "if(u != null){", // i.e. unix time is defined
                    "v = new Date(u * 1000);", // give top priority to UNIX time
                "}else{",
                    // create Date object representing midnight of the current day;
                    // this will provide us with our date defaults
                    // (note: clearTime() handles Daylight Saving Time automatically)
                    "dt = me.clearTime(new Date);",

                    "y = from(y, from(def.y, dt.getFullYear()));",
                    "m = from(m, from(def.m - 1, dt.getMonth()));",
                    "dayMatched = d !== undefined;",
                    "d = from(d, from(def.d, dt.getDate()));",

                    // Attempt to validate the day. Since it defaults to today, it may go out
                    // of range, for example parsing m/Y where the value is 02/2000 on the 31st of May.
                    // It will attempt to parse 2000/02/31, which will overflow to March and end up
                    // returning 03/2000. We only do this when we default the day. If an invalid day value
                    // was set to be parsed by the user, continue on and either let it overflow or return null
                    // depending on the strict value. This will be in line with the normal Date behaviour.

                    "if (!dayMatched) {",
                        "dt.setDate(1);",
                        "dt.setMonth(m);",
                        "dt.setFullYear(y);",

                        "daysInMonth = me.getDaysInMonth(dt);",
                        "if (d > daysInMonth) {",
                            "d = daysInMonth;",
                        "}",
                    "}",

                    "h  = from(h, from(def.h, dt.getHours()));",
                    "i  = from(i, from(def.i, dt.getMinutes()));",
                    "s  = from(s, from(def.s, dt.getSeconds()));",
                    "ms = from(ms, from(def.ms, dt.getMilliseconds()));",

                    "if(z >= 0 && y >= 0){",
                        // both the year and zero-based day of year are defined and >= 0.
                        // these 2 values alone provide sufficient info to create a full date object

                        // create Date object representing January 1st for the given year
                        // handle years < 100 appropriately
                        "v = me.add(new Date(y < 100 ? 100 : y, 0, 1, h, i, s, ms), me.YEAR, y < 100 ? y - 100 : 0);",

                        // then add day of year, checking for Date "rollover" if necessary
                        "v = !strict? v : (strict === true && (z <= 364 || (me.isLeapYear(v) && z <= 365))? me.add(v, me.DAY, z) : null);",
                    "}else if(strict === true && !me.isValid(y, m + 1, d, h, i, s, ms)){", // check for Date "rollover"
                        "v = null;", // invalid date, so return null
                    "}else{",
                        "if (W) {", // support ISO-8601
                            // http://en.wikipedia.org/wiki/ISO_week_date
                            //
                            // Mutually equivalent definitions for week 01 are:
                            // a. the week starting with the Monday which is nearest in time to 1 January
                            // b. the week with 4 January in it
                            // ... there are many others ...
                            //
                            // We'll use letter b above to determine the first week of the year.
                            //
                            // So, first get a Date object for January 4th of whatever calendar year is desired.
                            //
                            // Then, the first Monday of the year can easily be determined by (operating on this Date):
                            // 1. Getting the day of the week.
                            // 2. Subtracting that by one.
                            // 3. Multiplying that by 86400000 (one day in ms).
                            // 4. Subtracting this number of days (in ms) from the January 4 date (represented in ms).
                            //
                            // Example #1 ...
                            //
                            //       January 2012
                            //   Su Mo Tu We Th Fr Sa
                            //    1  2  3  4  5  6  7
                            //    8  9 10 11 12 13 14
                            //   15 16 17 18 19 20 21
                            //   22 23 24 25 26 27 28
                            //   29 30 31
                            //
                            // 1. January 4th is a Wednesday.
                            // 2. Its day number is 3.
                            // 3. Simply substract 2 days from Wednesday.
                            // 4. The first week of the year begins on Monday, January 2. Simple!
                            //
                            // Example #2 ...
                            //       January 1992
                            //   Su Mo Tu We Th Fr Sa
                            //             1  2  3  4
                            //    5  6  7  8  9 10 11
                            //   12 13 14 15 16 17 18
                            //   19 20 21 22 23 24 25
                            //   26 27 28 29 30 31
                            //
                            // 1. January 4th is a Saturday.
                            // 2. Its day number is 6.
                            // 3. Simply subtract 5 days from Saturday.
                            // 4. The first week of the year begins on Monday, December 30. Simple!
                            //
                            // v = Ext.Date.clearTime(new Date(week1monday.getTime() + ((W - 1) * 604800000)));
                            // (This is essentially doing the same thing as above but for the week rather than the day)
                            "year = y || (new Date()).getFullYear(),",
                            "jan4 = new Date(year, 0, 4, 0, 0, 0),",
                            "week1monday = new Date(jan4.getTime() - ((jan4.getDay() - 1) * 86400000));",
                            "v = Ext.Date.clearTime(new Date(week1monday.getTime() + ((W - 1) * 604800000)));",
                        "} else {",
                            // plain old Date object
                            // handle years < 100 properly
                            "v = me.add(new Date(y < 100 ? 100 : y, m, d, h, i, s, ms), me.YEAR, y < 100 ? y - 100 : 0);",
                        "}",
                    "}",
                "}",
            "}",

            "if(v){",
                // favor UTC offset over GMT offset
                "if(zz != null){",
                    // reset to UTC, then add offset
                    "v = me.add(v, me.SECOND, -v.getTimezoneOffset() * 60 - zz);",
                "}else if(o){",
                    // reset to GMT, then add offset
                    "v = me.add(v, me.MINUTE, -v.getTimezoneOffset() + (sn == '+'? -1 : 1) * (hr * 60 + mn));",
                "}",
            "}",

            "return v;"
          ].join('\n');

      // create private copy of Ext JS's `Ext.util.Format.format()` method
      // - to remove unnecessary dependency
      // - to resolve namespace conflict with MS-Ajax's implementation
      function xf(format) {
          var args = Array.prototype.slice.call(arguments, 1);
          return format.replace(numberTokenRe, function(m, i) {
              return args[i];
          });
      }

      Ext.apply(utilDate, {
        /**
         * Returns the current timestamp.
         * @return {Number} Milliseconds since UNIX epoch.
         * @method
         */
        now: Date.now || function() {
            return +new Date();
        },

        /**
         * @private
         * Private for now
         */
        toString: function(date) {
            var pad = Ext.String.leftPad;

            return date.getFullYear() + "-"
                + pad(date.getMonth() + 1, 2, '0') + "-"
                + pad(date.getDate(), 2, '0') + "T"
                + pad(date.getHours(), 2, '0') + ":"
                + pad(date.getMinutes(), 2, '0') + ":"
                + pad(date.getSeconds(), 2, '0');
        },

        /**
         * Returns the number of milliseconds between two dates.
         * @param {Date} dateA The first date.
         * @param {Date} [dateB=new Date()] (optional) The second date.
         * @return {Number} The difference in milliseconds
         */
        getElapsed: function(dateA, dateB) {
            return Math.abs(dateA - (dateB || utilDate.now()));
        },

        /**
         * Global flag which determines if strict date parsing should be used.
         * Strict date parsing will not roll-over invalid dates, which is the
         * default behavior of JavaScript Date objects.
         * (see {@link #parse} for more information)
         * @type Boolean
        */
        useStrict: false,

        // private
        formatCodeToRegex: function(character, currentGroup) {
            // Note: currentGroup - position in regex result array (see notes for Ext.Date.parseCodes below)
            var p = utilDate.parseCodes[character];

            if (p) {
              p = typeof p == 'function'? p() : p;
              utilDate.parseCodes[character] = p; // reassign function result to prevent repeated execution
            }

            return p ? Ext.applyIf({
              c: p.c ? xf(p.c, currentGroup || "{0}") : p.c
            }, p) : {
                g: 0,
                c: null,
                s: Ext.String.escapeRegex(character) // treat unrecognized characters as literals
            };
        },

        /**
         * An object hash in which each property is a date parsing function. The property name is the
         * format string which that function parses.
         *
         * This object is automatically populated with date parsing functions as
         * date formats are requested for Ext standard formatting strings.
         *
         * Custom parsing functions may be inserted into this object, keyed by a name which from then on
         * may be used as a format string to {@link #parse}.
         *
         * Example:
         *
         *     Ext.Date.parseFunctions['x-date-format'] = myDateParser;
         *
         * A parsing function should return a Date object, and is passed the following parameters:<div class="mdetail-params"><ul>
         * <li><code>date</code> : String<div class="sub-desc">The date string to parse.</div></li>
         * <li><code>strict</code> : Boolean<div class="sub-desc">True to validate date strings while parsing
         * (i.e. prevent JavaScript Date "rollover") (The default must be `false`).
         * Invalid date strings should return `null` when parsed.</div></li>
         * </ul></div>
         *
         * To enable Dates to also be _formatted_ according to that format, a corresponding
         * formatting function must be placed into the {@link #formatFunctions} property.
         * @property parseFunctions
         * @type Object
         */
        parseFunctions: {
            "MS": function(input, strict) {
                // note: the timezone offset is ignored since the MS Ajax server sends
                // a UTC milliseconds-since-Unix-epoch value (negative values are allowed)
                var r = (input || '').match(MSFormatRe);
                return r ? new Date(((r[1] || '') + r[2]) * 1) : null;
            },
            "time": function(input, strict) {
                var num = parseInt(input, 10);
                if (num || num === 0) {
                    return new Date(num);
                }
                return null;
            },
            "timestamp": function(input, strict) {
                var num = parseInt(input, 10);
                if (num || num === 0) {
                    return new Date(num * 1000);
                }
                return null;
            }
        },
        parseRegexes: [],

        /**
         * An object hash in which each property is a date formatting function. The property name is the
         * format string which corresponds to the produced formatted date string.
         *
         * This object is automatically populated with date formatting functions as
         * date formats are requested for Ext standard formatting strings.
         *
         * Custom formatting functions may be inserted into this object, keyed by a name which from then on
         * may be used as a format string to {@link #format}.
         *
         * Example:
         *
         *     Ext.Date.formatFunctions['x-date-format'] = myDateFormatter;
         *
         * A formatting function should return a string representation of the passed Date object, and is passed the following parameters:<div class="mdetail-params"><ul>
         * <li><code>date</code> : Date<div class="sub-desc">The Date to format.</div></li>
         * </ul></div>
         *
         * To enable date strings to also be _parsed_ according to that format, a corresponding
         * parsing function must be placed into the {@link #parseFunctions} property.
         * @property formatFunctions
         * @type Object
         */
        formatFunctions: {
            "MS": function() {
                // UTC milliseconds since Unix epoch (MS-AJAX serialized date format (MRSF))
                return '\\/Date(' + this.getTime() + ')\\/';
            },
            "time": function(){
                return this.getTime().toString();
            },
            "timestamp": function(){
                return utilDate.format(this, 'U');
            }
        },

        y2kYear : 50,

        /**
         * Date interval constant
         * @type String
         */
        MILLI : "ms",

        /**
         * Date interval constant
         * @type String
         */
        SECOND : "s",

        /**
         * Date interval constant
         * @type String
         */
        MINUTE : "mi",

        /** Date interval constant
         * @type String
         */
        HOUR : "h",

        /**
         * Date interval constant
         * @type String
         */
        DAY : "d",

        /**
         * Date interval constant
         * @type String
         */
        MONTH : "mo",

        /**
         * Date interval constant
         * @type String
         */
        YEAR : "y",

        /**
         * An object hash containing default date values used during date parsing.
         *
         * The following properties are available:<div class="mdetail-params"><ul>
         * <li><code>y</code> : Number<div class="sub-desc">The default year value. (defaults to undefined)</div></li>
         * <li><code>m</code> : Number<div class="sub-desc">The default 1-based month value. (defaults to undefined)</div></li>
         * <li><code>d</code> : Number<div class="sub-desc">The default day value. (defaults to undefined)</div></li>
         * <li><code>h</code> : Number<div class="sub-desc">The default hour value. (defaults to undefined)</div></li>
         * <li><code>i</code> : Number<div class="sub-desc">The default minute value. (defaults to undefined)</div></li>
         * <li><code>s</code> : Number<div class="sub-desc">The default second value. (defaults to undefined)</div></li>
         * <li><code>ms</code> : Number<div class="sub-desc">The default millisecond value. (defaults to undefined)</div></li>
         * </ul></div>
         *
         * Override these properties to customize the default date values used by the {@link #parse} method.
         *
         * __Note:__ In countries which experience Daylight Saving Time (i.e. DST), the `h`, `i`, `s`
         * and `ms` properties may coincide with the exact time in which DST takes effect.
         * It is the responsibility of the developer to account for this.
         *
         * Example Usage:
         *
         *     // set default day value to the first day of the month
         *     Ext.Date.defaults.d = 1;
         *
         *     // parse a February date string containing only year and month values.
         *     // setting the default day value to 1 prevents weird date rollover issues
         *     // when attempting to parse the following date string on, for example, March 31st 2009.
         *     Ext.Date.parse('2009-02', 'Y-m'); // returns a Date object representing February 1st 2009
         *
         * @property defaults
         * @type Object
         */
        defaults: {},

        //<locale type="array">
        /**
         * @property {String[]} dayNames
         * An array of textual day names.
         * Override these values for international dates.
         *
         * Example:
         *
         *     Ext.Date.dayNames = [
         *         'SundayInYourLang',
         *         'MondayInYourLang'
         *         // ...
         *     ];
         */
        dayNames : [
            "Sunday",
            "Monday",
            "Tuesday",
            "Wednesday",
            "Thursday",
            "Friday",
            "Saturday"
        ],
        //</locale>

        //<locale type="array">
        /**
         * @property {String[]} monthNames
         * An array of textual month names.
         * Override these values for international dates.
         *
         * Example:
         *
         *     Ext.Date.monthNames = [
         *         'JanInYourLang',
         *         'FebInYourLang'
         *         // ...
         *     ];
         */
        monthNames : [
            "January",
            "February",
            "March",
            "April",
            "May",
            "June",
            "July",
            "August",
            "September",
            "October",
            "November",
            "December"
        ],
        //</locale>

        //<locale type="object">
        /**
         * @property {Object} monthNumbers
         * An object hash of zero-based JavaScript month numbers (with short month names as keys. **Note:** keys are case-sensitive).
         * Override these values for international dates.
         *
         * Example:
         *
         *     Ext.Date.monthNumbers = {
         *         'LongJanNameInYourLang': 0,
         *         'ShortJanNameInYourLang':0,
         *         'LongFebNameInYourLang':1,
         *         'ShortFebNameInYourLang':1
         *         // ...
         *     };
         */
        monthNumbers : {
            January: 0,
            Jan: 0,
            February: 1,
            Feb: 1,
            March: 2,
            Mar: 2,
            April: 3,
            Apr: 3,
            May: 4,
            June: 5,
            Jun: 5,
            July: 6,
            Jul: 6,
            August: 7,
            Aug: 7,
            September: 8,
            Sep: 8,
            October: 9,
            Oct: 9,
            November: 10,
            Nov: 10,
            December: 11,
            Dec: 11
        },
        //</locale>

        //<locale>
        /**
         * @property {String} defaultFormat
         * The date format string that the {@link Ext.util.Format#dateRenderer}
         * and {@link Ext.util.Format#date} functions use.  See {@link Ext.Date} for details.
         *
         * This may be overridden in a locale file.
         */
        defaultFormat : "m/d/Y",
        //</locale>
        //<locale type="function">
        /**
         * Get the short month name for the given month number.
         * Override this function for international dates.
         * @param {Number} month A zero-based JavaScript month number.
         * @return {String} The short month name.
         */
        getShortMonthName : function(month) {
            return Ext.Date.monthNames[month].substring(0, 3);
        },
        //</locale>

        //<locale type="function">
        /**
         * Get the short day name for the given day number.
         * Override this function for international dates.
         * @param {Number} day A zero-based JavaScript day number.
         * @return {String} The short day name.
         */
        getShortDayName : function(day) {
            return Ext.Date.dayNames[day].substring(0, 3);
        },
        //</locale>

        //<locale type="function">
        /**
         * Get the zero-based JavaScript month number for the given short/full month name.
         * Override this function for international dates.
         * @param {String} name The short/full month name.
         * @return {Number} The zero-based JavaScript month number.
         */
        getMonthNumber : function(name) {
            // handle camel casing for English month names (since the keys for the Ext.Date.monthNumbers hash are case sensitive)
            return Ext.Date.monthNumbers[name.substring(0, 1).toUpperCase() + name.substring(1, 3).toLowerCase()];
        },
        //</locale>

        /**
         * Checks if the specified format contains hour information
         * @param {String} format The format to check
         * @return {Boolean} True if the format contains hour information
         * @method
         */
        formatContainsHourInfo : function(format){
            return hourInfoRe.test(format.replace(stripEscapeRe, ''));
        },

        /**
         * Checks if the specified format contains information about
         * anything other than the time.
         * @param {String} format The format to check
         * @return {Boolean} True if the format contains information about
         * date/day information.
         * @method
         */
        formatContainsDateInfo : function(format){
            return dateInfoRe.test(format.replace(stripEscapeRe, ''));
        },

        /**
         * Removes all escaping for a date format string. In date formats,
         * using a '\' can be used to escape special characters.
         * @param {String} format The format to unescape
         * @return {String} The unescaped format
         * @method
         */
        unescapeFormat: function(format) {
            // Escape the format, since \ can be used to escape special
            // characters in a date format. For example, in a Spanish
            // locale the format may be: 'd \\de F \\de Y'
            return format.replace(slashRe, '');
        },

        /**
         * The base format-code to formatting-function hashmap used by the {@link #format} method.
         * Formatting functions are strings (or functions which return strings) which
         * will return the appropriate value when evaluated in the context of the Date object
         * from which the {@link #format} method is called.
         * Add to / override these mappings for custom date formatting.
         *
         * __Note:__ Ext.Date.format() treats characters as literals if an appropriate mapping cannot be found.
         *
         * Example:
         *
         *     Ext.Date.formatCodes.x = "Ext.util.Format.leftPad(this.getDate(), 2, '0')";
         *     console.log(Ext.Date.format(new Date(), 'X'); // returns the current day of the month
         * @type Object
         */
        formatCodes : {
            d: "Ext.String.leftPad(this.getDate(), 2, '0')",
            D: "Ext.Date.getShortDayName(this.getDay())", // get localized short day name
            j: "this.getDate()",
            l: "Ext.Date.dayNames[this.getDay()]",
            N: "(this.getDay() ? this.getDay() : 7)",
            S: "Ext.Date.getSuffix(this)",
            w: "this.getDay()",
            z: "Ext.Date.getDayOfYear(this)",
            W: "Ext.String.leftPad(Ext.Date.getWeekOfYear(this), 2, '0')",
            F: "Ext.Date.monthNames[this.getMonth()]",
            m: "Ext.String.leftPad(this.getMonth() + 1, 2, '0')",
            M: "Ext.Date.getShortMonthName(this.getMonth())", // get localized short month name
            n: "(this.getMonth() + 1)",
            t: "Ext.Date.getDaysInMonth(this)",
            L: "(Ext.Date.isLeapYear(this) ? 1 : 0)",
            o: "(this.getFullYear() + (Ext.Date.getWeekOfYear(this) == 1 && this.getMonth() > 0 ? +1 : (Ext.Date.getWeekOfYear(this) >= 52 && this.getMonth() < 11 ? -1 : 0)))",
            Y: "Ext.String.leftPad(this.getFullYear(), 4, '0')",
            y: "('' + this.getFullYear()).substring(2, 4)",
            a: "(this.getHours() < 12 ? 'am' : 'pm')",
            A: "(this.getHours() < 12 ? 'AM' : 'PM')",
            g: "((this.getHours() % 12) ? this.getHours() % 12 : 12)",
            G: "this.getHours()",
            h: "Ext.String.leftPad((this.getHours() % 12) ? this.getHours() % 12 : 12, 2, '0')",
            H: "Ext.String.leftPad(this.getHours(), 2, '0')",
            i: "Ext.String.leftPad(this.getMinutes(), 2, '0')",
            s: "Ext.String.leftPad(this.getSeconds(), 2, '0')",
            u: "Ext.String.leftPad(this.getMilliseconds(), 3, '0')",
            O: "Ext.Date.getGMTOffset(this)",
            P: "Ext.Date.getGMTOffset(this, true)",
            T: "Ext.Date.getTimezone(this)",
            Z: "(this.getTimezoneOffset() * -60)",

            c: function() { // ISO-8601 -- GMT format
                var c, code, i, l, e;
                for (c = "Y-m-dTH:i:sP", code = [], i = 0, l = c.length; i < l; ++i) {
                    e = c.charAt(i);
                    code.push(e == "T" ? "'T'" : utilDate.getFormatCode(e)); // treat T as a character literal
                }
                return code.join(" + ");
            },
            /*
            c: function() { // ISO-8601 -- UTC format
                return [
                  "this.getUTCFullYear()", "'-'",
                  "Ext.util.Format.leftPad(this.getUTCMonth() + 1, 2, '0')", "'-'",
                  "Ext.util.Format.leftPad(this.getUTCDate(), 2, '0')",
                  "'T'",
                  "Ext.util.Format.leftPad(this.getUTCHours(), 2, '0')", "':'",
                  "Ext.util.Format.leftPad(this.getUTCMinutes(), 2, '0')", "':'",
                  "Ext.util.Format.leftPad(this.getUTCSeconds(), 2, '0')",
                  "'Z'"
                ].join(" + ");
            },
            */

            U: "Math.round(this.getTime() / 1000)"
        },

        /**
         * Checks if the passed Date parameters will cause a JavaScript Date "rollover".
         * @param {Number} year 4-digit year
         * @param {Number} month 1-based month-of-year
         * @param {Number} day Day of month
         * @param {Number} hour (optional) Hour
         * @param {Number} minute (optional) Minute
         * @param {Number} second (optional) Second
         * @param {Number} millisecond (optional) Millisecond
         * @return {Boolean} `true` if the passed parameters do not cause a Date "rollover", `false` otherwise.
         */
        isValid : function(y, m, d, h, i, s, ms) {
            // setup defaults
            h = h || 0;
            i = i || 0;
            s = s || 0;
            ms = ms || 0;

            // Special handling for year < 100
            var dt = utilDate.add(new Date(y < 100 ? 100 : y, m - 1, d, h, i, s, ms), utilDate.YEAR, y < 100 ? y - 100 : 0);

            return y == dt.getFullYear() &&
                m == dt.getMonth() + 1 &&
                d == dt.getDate() &&
                h == dt.getHours() &&
                i == dt.getMinutes() &&
                s == dt.getSeconds() &&
                ms == dt.getMilliseconds();
        },

        /**
         * Parses the passed string using the specified date format.
         * Note that this function expects normal calendar dates, meaning that months are 1-based (i.e. 1 = January).
         * The {@link #defaults} hash will be used for any date value (i.e. year, month, day, hour, minute, second or millisecond)
         * which cannot be found in the passed string. If a corresponding default date value has not been specified in the {@link #defaults} hash,
         * the current date's year, month, day or DST-adjusted zero-hour time value will be used instead.
         * Keep in mind that the input date string must precisely match the specified format string
         * in order for the parse operation to be successful (failed parse operations return a null value).
         *
         * Example:
         *
         *     //dt = Fri May 25 2007 (current date)
         *     var dt = new Date();
         *
         *     //dt = Thu May 25 2006 (today&#39;s month/day in 2006)
         *     dt = Ext.Date.parse("2006", "Y");
         *
         *     //dt = Sun Jan 15 2006 (all date parts specified)
         *     dt = Ext.Date.parse("2006-01-15", "Y-m-d");
         *
         *     //dt = Sun Jan 15 2006 15:20:01
         *     dt = Ext.Date.parse("2006-01-15 3:20:01 PM", "Y-m-d g:i:s A");
         *
         *     // attempt to parse Sun Feb 29 2006 03:20:01 in strict mode
         *     dt = Ext.Date.parse("2006-02-29 03:20:01", "Y-m-d H:i:s", true); // returns null
         *
         * @param {String} input The raw date string.
         * @param {String} format The expected date string format.
         * @param {Boolean} [strict=false] (optional) `true` to validate date strings while parsing (i.e. prevents JavaScript Date "rollover").
         * Invalid date strings will return `null` when parsed.
         * @return {Date} The parsed Date.
         */
        parse : function(input, format, strict) {
            var p = utilDate.parseFunctions;
            if (p[format] == null) {
                utilDate.createParser(format);
            }
            return p[format].call(utilDate, input, Ext.isDefined(strict) ? strict : utilDate.useStrict);
        },

        // Backwards compat
        parseDate: function(input, format, strict){
            return utilDate.parse(input, format, strict);
        },

        // private
        getFormatCode : function(character) {
            var f = utilDate.formatCodes[character];

            if (f) {
              f = typeof f == 'function'? f() : f;
              utilDate.formatCodes[character] = f; // reassign function result to prevent repeated execution
            }

            // note: unknown characters are treated as literals
            return f || ("'" + Ext.String.escape(character) + "'");
        },

        // private
        createFormat : function(format) {
            var code = [],
                special = false,
                ch = '',
                i;

            for (i = 0; i < format.length; ++i) {
                ch = format.charAt(i);
                if (!special && ch == "\\") {
                    special = true;
                } else if (special) {
                    special = false;
                    code.push("'" + Ext.String.escape(ch) + "'");
                } else {
                    code.push(utilDate.getFormatCode(ch));
                }
            }
            utilDate.formatFunctions[format] = Ext.functionFactory("return " + code.join('+'));
        },

        // private
        createParser : function(format) {
            var regexNum = utilDate.parseRegexes.length,
                currentGroup = 1,
                calc = [],
                regex = [],
                special = false,
                ch = "",
                i = 0,
                len = format.length,
                atEnd = [],
                obj;

            for (; i < len; ++i) {
                ch = format.charAt(i);
                if (!special && ch == "\\") {
                    special = true;
                } else if (special) {
                    special = false;
                    regex.push(Ext.String.escape(ch));
                } else {
                    obj = utilDate.formatCodeToRegex(ch, currentGroup);
                    currentGroup += obj.g;
                    regex.push(obj.s);
                    if (obj.g && obj.c) {
                        if (obj.calcAtEnd) {
                            atEnd.push(obj.c);
                        } else {
                            calc.push(obj.c);
                        }
                    }
                }
            }

            calc = calc.concat(atEnd);

            utilDate.parseRegexes[regexNum] = new RegExp("^" + regex.join('') + "$", 'i');
            utilDate.parseFunctions[format] = Ext.functionFactory("input", "strict", xf(code, regexNum, calc.join('')));
        },

        // private
        parseCodes : {
            /*
             * Notes:
             * g = {Number} calculation group (0 or 1. only group 1 contributes to date calculations.)
             * c = {String} calculation method (required for group 1. null for group 0. {0} = currentGroup - position in regex result array)
             * s = {String} regex pattern. all matches are stored in results[], and are accessible by the calculation mapped to 'c'
             */
            d: {
                g:1,
                c:"d = parseInt(results[{0}], 10);\n",
                s:"(3[0-1]|[1-2][0-9]|0[1-9])" // day of month with leading zeroes (01 - 31)
            },
            j: {
                g:1,
                c:"d = parseInt(results[{0}], 10);\n",
                s:"(3[0-1]|[1-2][0-9]|[1-9])" // day of month without leading zeroes (1 - 31)
            },
            D: function() {
                for (var a = [], i = 0; i < 7; a.push(utilDate.getShortDayName(i)), ++i); // get localised short day names
                return {
                    g:0,
                    c:null,
                    s:"(?:" + a.join("|") +")"
                };
            },
            l: function() {
                return {
                    g:0,
                    c:null,
                    s:"(?:" + utilDate.dayNames.join("|") + ")"
                };
            },
            N: {
                g:0,
                c:null,
                s:"[1-7]" // ISO-8601 day number (1 (monday) - 7 (sunday))
            },
            //<locale type="object" property="parseCodes">
            S: {
                g:0,
                c:null,
                s:"(?:st|nd|rd|th)"
            },
            //</locale>
            w: {
                g:0,
                c:null,
                s:"[0-6]" // JavaScript day number (0 (sunday) - 6 (saturday))
            },
            z: {
                g:1,
                c:"z = parseInt(results[{0}], 10);\n",
                s:"(\\d{1,3})" // day of the year (0 - 364 (365 in leap years))
            },
            W: {
                g:1,
                c:"W = parseInt(results[{0}], 10);\n",
                s:"(\\d{2})" // ISO-8601 week number (with leading zero)
            },
            F: function() {
                return {
                    g:1,
                    c:"m = parseInt(me.getMonthNumber(results[{0}]), 10);\n", // get localised month number
                    s:"(" + utilDate.monthNames.join("|") + ")"
                };
            },
            M: function() {
                for (var a = [], i = 0; i < 12; a.push(utilDate.getShortMonthName(i)), ++i); // get localised short month names
                return Ext.applyIf({
                    s:"(" + a.join("|") + ")"
                }, utilDate.formatCodeToRegex("F"));
            },
            m: {
                g:1,
                c:"m = parseInt(results[{0}], 10) - 1;\n",
                s:"(1[0-2]|0[1-9])" // month number with leading zeros (01 - 12)
            },
            n: {
                g:1,
                c:"m = parseInt(results[{0}], 10) - 1;\n",
                s:"(1[0-2]|[1-9])" // month number without leading zeros (1 - 12)
            },
            t: {
                g:0,
                c:null,
                s:"(?:\\d{2})" // no. of days in the month (28 - 31)
            },
            L: {
                g:0,
                c:null,
                s:"(?:1|0)"
            },
            o: {
                g: 1,
                c: "y = parseInt(results[{0}], 10);\n",
                s: "(\\d{4})" // ISO-8601 year number (with leading zero)

            },
            Y: {
                g:1,
                c:"y = parseInt(results[{0}], 10);\n",
                s:"(\\d{4})" // 4-digit year
            },
            y: {
                g:1,
                c:"var ty = parseInt(results[{0}], 10);\n"
                    + "y = ty > me.y2kYear ? 1900 + ty : 2000 + ty;\n", // 2-digit year
                s:"(\\d{1,2})"
            },
            /*
             * In the am/pm parsing routines, we allow both upper and lower case
             * even though it doesn't exactly match the spec. It gives much more flexibility
             * in being able to specify case insensitive regexes.
             */
            //<locale type="object" property="parseCodes">
            a: {
                g:1,
                c:"if (/(am)/i.test(results[{0}])) {\n"
                    + "if (!h || h == 12) { h = 0; }\n"
                    + "} else { if (!h || h < 12) { h = (h || 0) + 12; }}",
                s:"(am|pm|AM|PM)",
                calcAtEnd: true
            },
            //</locale>
            //<locale type="object" property="parseCodes">
            A: {
                g:1,
                c:"if (/(am)/i.test(results[{0}])) {\n"
                    + "if (!h || h == 12) { h = 0; }\n"
                    + "} else { if (!h || h < 12) { h = (h || 0) + 12; }}",
                s:"(AM|PM|am|pm)",
                calcAtEnd: true
            },
            //</locale>
            g: {
                g:1,
                c:"h = parseInt(results[{0}], 10);\n",
                s:"(1[0-2]|[0-9])" //  12-hr format of an hour without leading zeroes (1 - 12)
            },
            G: {
                g:1,
                c:"h = parseInt(results[{0}], 10);\n",
                s:"(2[0-3]|1[0-9]|[0-9])" // 24-hr format of an hour without leading zeroes (0 - 23)
            },
            h: {
                g:1,
                c:"h = parseInt(results[{0}], 10);\n",
                s:"(1[0-2]|0[1-9])" //  12-hr format of an hour with leading zeroes (01 - 12)
            },
            H: {
                g:1,
                c:"h = parseInt(results[{0}], 10);\n",
                s:"(2[0-3]|[0-1][0-9])" //  24-hr format of an hour with leading zeroes (00 - 23)
            },
            i: {
                g:1,
                c:"i = parseInt(results[{0}], 10);\n",
                s:"([0-5][0-9])" // minutes with leading zeros (00 - 59)
            },
            s: {
                g:1,
                c:"s = parseInt(results[{0}], 10);\n",
                s:"([0-5][0-9])" // seconds with leading zeros (00 - 59)
            },
            u: {
                g:1,
                c:"ms = results[{0}]; ms = parseInt(ms, 10)/Math.pow(10, ms.length - 3);\n",
                s:"(\\d+)" // decimal fraction of a second (minimum = 1 digit, maximum = unlimited)
            },
            O: {
                g:1,
                c:[
                    "o = results[{0}];",
                    "var sn = o.substring(0,1),", // get + / - sign
                        "hr = o.substring(1,3)*1 + Math.floor(o.substring(3,5) / 60),", // get hours (performs minutes-to-hour conversion also, just in case)
                        "mn = o.substring(3,5) % 60;", // get minutes
                    "o = ((-12 <= (hr*60 + mn)/60) && ((hr*60 + mn)/60 <= 14))? (sn + Ext.String.leftPad(hr, 2, '0') + Ext.String.leftPad(mn, 2, '0')) : null;\n" // -12hrs <= GMT offset <= 14hrs
                ].join("\n"),
                s: "([+-]\\d{4})" // GMT offset in hrs and mins
            },
            P: {
                g:1,
                c:[
                    "o = results[{0}];",
                    "var sn = o.substring(0,1),", // get + / - sign
                        "hr = o.substring(1,3)*1 + Math.floor(o.substring(4,6) / 60),", // get hours (performs minutes-to-hour conversion also, just in case)
                        "mn = o.substring(4,6) % 60;", // get minutes
                    "o = ((-12 <= (hr*60 + mn)/60) && ((hr*60 + mn)/60 <= 14))? (sn + Ext.String.leftPad(hr, 2, '0') + Ext.String.leftPad(mn, 2, '0')) : null;\n" // -12hrs <= GMT offset <= 14hrs
                ].join("\n"),
                s: "([+-]\\d{2}:\\d{2})" // GMT offset in hrs and mins (with colon separator)
            },
            T: {
                g:0,
                c:null,
                s:"[A-Z]{1,5}" // timezone abbrev. may be between 1 - 5 chars
            },
            Z: {
                g:1,
                c:"zz = results[{0}] * 1;\n" // -43200 <= UTC offset <= 50400
                      + "zz = (-43200 <= zz && zz <= 50400)? zz : null;\n",
                s:"([+-]?\\d{1,5})" // leading '+' sign is optional for UTC offset
            },
            c: function() {
                var calc = [],
                    arr = [
                        utilDate.formatCodeToRegex("Y", 1), // year
                        utilDate.formatCodeToRegex("m", 2), // month
                        utilDate.formatCodeToRegex("d", 3), // day
                        utilDate.formatCodeToRegex("H", 4), // hour
                        utilDate.formatCodeToRegex("i", 5), // minute
                        utilDate.formatCodeToRegex("s", 6), // second
                        {c:"ms = results[7] || '0'; ms = parseInt(ms, 10)/Math.pow(10, ms.length - 3);\n"}, // decimal fraction of a second (minimum = 1 digit, maximum = unlimited)
                        {c:[ // allow either "Z" (i.e. UTC) or "-0530" or "+08:00" (i.e. UTC offset) timezone delimiters. assumes local timezone if no timezone is specified
                            "if(results[8]) {", // timezone specified
                                "if(results[8] == 'Z'){",
                                    "zz = 0;", // UTC
                                "}else if (results[8].indexOf(':') > -1){",
                                    utilDate.formatCodeToRegex("P", 8).c, // timezone offset with colon separator
                                "}else{",
                                    utilDate.formatCodeToRegex("O", 8).c, // timezone offset without colon separator
                                "}",
                            "}"
                        ].join('\n')}
                    ],
                    i,
                    l;

                for (i = 0, l = arr.length; i < l; ++i) {
                    calc.push(arr[i].c);
                }

                return {
                    g:1,
                    c:calc.join(""),
                    s:[
                        arr[0].s, // year (required)
                        "(?:", "-", arr[1].s, // month (optional)
                            "(?:", "-", arr[2].s, // day (optional)
                                "(?:",
                                    "(?:T| )?", // time delimiter -- either a "T" or a single blank space
                                    arr[3].s, ":", arr[4].s,  // hour AND minute, delimited by a single colon (optional). MUST be preceded by either a "T" or a single blank space
                                    "(?::", arr[5].s, ")?", // seconds (optional)
                                    "(?:(?:\\.|,)(\\d+))?", // decimal fraction of a second (e.g. ",12345" or ".98765") (optional)
                                    "(Z|(?:[-+]\\d{2}(?::)?\\d{2}))?", // "Z" (UTC) or "-0530" (UTC offset without colon delimiter) or "+08:00" (UTC offset with colon delimiter) (optional)
                                ")?",
                            ")?",
                        ")?"
                    ].join("")
                };
            },
            U: {
                g:1,
                c:"u = parseInt(results[{0}], 10);\n",
                s:"(-?\\d+)" // leading minus sign indicates seconds before UNIX epoch
            }
        },

        //Old Ext.Date prototype methods.
        // private
        dateFormat: function(date, format) {
            return utilDate.format(date, format);
        },

        /**
         * Compares if two dates are equal by comparing their values.
         * @param {Date} date1
         * @param {Date} date2
         * @return {Boolean} `true` if the date values are equal
         */
        isEqual: function(date1, date2) {
            // check we have 2 date objects
            if (date1 && date2) {
                return (date1.getTime() === date2.getTime());
            }
            // one or both isn't a date, only equal if both are falsey
            return !(date1 || date2);
        },

        /**
         * Formats a date given the supplied format string.
         * @param {Date} date The date to format
         * @param {String} format The format string
         * @return {String} The formatted date or an empty string if date parameter is not a JavaScript Date object
         */
        format: function(date, format) {
            var formatFunctions = utilDate.formatFunctions;

            if (!Ext.isDate(date)) {
                return '';
            }

            if (formatFunctions[format] == null) {
                utilDate.createFormat(format);
            }

            return formatFunctions[format].call(date) + '';
        },

        /**
         * Get the timezone abbreviation of the current date (equivalent to the format specifier 'T').
         *
         * __Note:__ The date string returned by the JavaScript Date object's `toString()` method varies
         * between browsers (e.g. FF vs IE) and system region settings (e.g. IE in Asia vs IE in America).
         * For a given date string e.g. "Thu Oct 25 2007 22:55:35 GMT+0800 (Malay Peninsula Standard Time)",
         * getTimezone() first tries to get the timezone abbreviation from between a pair of parentheses
         * (which may or may not be present), failing which it proceeds to get the timezone abbreviation
         * from the GMT offset portion of the date string.
         * @param {Date} date The date
         * @return {String} The abbreviated timezone name (e.g. 'CST', 'PDT', 'EDT', 'MPST' ...).
         */
        getTimezone : function(date) {
            // the following list shows the differences between date strings from different browsers on a WinXP SP2 machine from an Asian locale:
            //
            // Opera  : "Thu, 25 Oct 2007 22:53:45 GMT+0800" -- shortest (weirdest) date string of the lot
            // Safari : "Thu Oct 25 2007 22:55:35 GMT+0800 (Malay Peninsula Standard Time)" -- value in parentheses always gives the correct timezone (same as FF)
            // FF     : "Thu Oct 25 2007 22:55:35 GMT+0800 (Malay Peninsula Standard Time)" -- value in parentheses always gives the correct timezone
            // IE     : "Thu Oct 25 22:54:35 UTC+0800 2007" -- (Asian system setting) look for 3-4 letter timezone abbrev
            // IE     : "Thu Oct 25 17:06:37 PDT 2007" -- (American system setting) look for 3-4 letter timezone abbrev
            //
            // this crazy regex attempts to guess the correct timezone abbreviation despite these differences.
            // step 1: (?:\((.*)\) -- find timezone in parentheses
            // step 2: ([A-Z]{1,4})(?:[\-+][0-9]{4})?(?: -?\d+)?) -- if nothing was found in step 1, find timezone from timezone offset portion of date string
            // step 3: remove all non uppercase characters found in step 1 and 2
            return date.toString().replace(/^.* (?:\((.*)\)|([A-Z]{1,5})(?:[\-+][0-9]{4})?(?: -?\d+)?)$/, "$1$2").replace(/[^A-Z]/g, "");
        },

        /**
         * Get the offset from GMT of the current date (equivalent to the format specifier 'O').
         * @param {Date} date The date
         * @param {Boolean} [colon=false] (optional) true to separate the hours and minutes with a colon.
         * @return {String} The 4-character offset string prefixed with + or - (e.g. '-0600').
         */
        getGMTOffset : function(date, colon) {
            var offset = date.getTimezoneOffset();
            return (offset > 0 ? "-" : "+")
                + Ext.String.leftPad(Math.floor(Math.abs(offset) / 60), 2, "0")
                + (colon ? ":" : "")
                + Ext.String.leftPad(Math.abs(offset % 60), 2, "0");
        },

        /**
         * Get the numeric day number of the year, adjusted for leap year.
         * @param {Date} date The date
         * @return {Number} 0 to 364 (365 in leap years).
         */
        getDayOfYear: function(date) {
            var num = 0,
                d = Ext.Date.clone(date),
                m = date.getMonth(),
                i;

            for (i = 0, d.setDate(1), d.setMonth(0); i < m; d.setMonth(++i)) {
                num += utilDate.getDaysInMonth(d);
            }
            return num + date.getDate() - 1;
        },

        /**
         * Get the numeric ISO-8601 week number of the year.
         * (equivalent to the format specifier 'W', but without a leading zero).
         * @param {Date} date The date
         * @return {Number} 1 to 53
         * @method
         */
        getWeekOfYear : (function() {
            // adapted from http://www.merlyn.demon.co.uk/weekcalc.htm
            var ms1d = 864e5, // milliseconds in a day
                ms7d = 7 * ms1d; // milliseconds in a week

            return function(date) { // return a closure so constants get calculated only once
                var DC3 = Date.UTC(date.getFullYear(), date.getMonth(), date.getDate() + 3) / ms1d, // an Absolute Day Number
                    AWN = Math.floor(DC3 / 7), // an Absolute Week Number
                    Wyr = new Date(AWN * ms7d).getUTCFullYear();

                return AWN - Math.floor(Date.UTC(Wyr, 0, 7) / ms7d) + 1;
            };
        }()),

        /**
         * Checks if the current date falls within a leap year.
         * @param {Date} date The date
         * @return {Boolean} True if the current date falls within a leap year, false otherwise.
         */
        isLeapYear : function(date) {
            var year = date.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:
         *
         *     var dt = new Date('1/10/2007'),
         *         firstDay = Ext.Date.getFirstDayOfMonth(dt);
         *     console.log(Ext.Date.dayNames[firstDay]); // output: 'Monday'
         *
         * @param {Date} date The date
         * @return {Number} The day number (0-6).
         */
        getFirstDayOfMonth : function(date) {
            var day = (date.getDay() - (date.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:
         *
         *     var dt = new Date('1/10/2007'),
         *         lastDay = Ext.Date.getLastDayOfMonth(dt);
         *     console.log(Ext.Date.dayNames[lastDay]); // output: 'Wednesday'
         *
         * @param {Date} date The date
         * @return {Number} The day number (0-6).
         */
        getLastDayOfMonth : function(date) {
            return utilDate.getLastDateOfMonth(date).getDay();
        },

        /**
         * Get the date of the first day of the month in which this date resides.
         * @param {Date} date The date
         * @return {Date}
         */
        getFirstDateOfMonth : function(date) {
            return new Date(date.getFullYear(), date.getMonth(), 1);
        },

        /**
         * Get the date of the last day of the month in which this date resides.
         * @param {Date} date The date
         * @return {Date}
         */
        getLastDateOfMonth : function(date) {
            return new Date(date.getFullYear(), date.getMonth(), utilDate.getDaysInMonth(date));
        },

        /**
         * Get the number of days in the current month, adjusted for leap year.
         * @param {Date} date The date
         * @return {Number} The number of days in the month.
         * @method
         */
        getDaysInMonth: (function() {
            var daysInMonth = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];

            return function(date) { // return a closure for efficiency
                var m = date.getMonth();

                return m == 1 && utilDate.isLeapYear(date) ? 29 : daysInMonth[m];
            };
        }()),

        //<locale type="function">
        /**
         * Get the English ordinal suffix of the current day (equivalent to the format specifier 'S').
         * @param {Date} date The date
         * @return {String} 'st, 'nd', 'rd' or 'th'.
         */
        getSuffix : function(date) {
            switch (date.getDate()) {
                case 1:
                case 21:
                case 31:
                    return "st";
                case 2:
                case 22:
                    return "nd";
                case 3:
                case 23:
                    return "rd";
                default:
                    return "th";
            }
        },
        //</locale>

        /**
         * 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:
         *
         *     //wrong way:
         *     var orig = new Date('10/1/2006');
         *     var copy = orig;
         *     copy.setDate(5);
         *     console.log(orig);  // returns 'Thu Oct 05 2006'!
         *
         *     //correct way:
         *     var orig = new Date('10/1/2006'),
         *         copy = Ext.Date.clone(orig);
         *     copy.setDate(5);
         *     console.log(orig);  // returns 'Thu Oct 01 2006'
         *
         * @param {Date} date The date.
         * @return {Date} The new Date instance.
         */
        clone : function(date) {
            return new Date(date.getTime());
        },

        /**
         * Checks if the current date is affected by Daylight Saving Time (DST).
         * @param {Date} date The date
         * @return {Boolean} `true` if the current date is affected by DST.
         */
        isDST : function(date) {
            // adapted from http://sencha.com/forum/showthread.php?p=247172#post247172
            // courtesy of @geoffrey.mcgill
            return new Date(date.getFullYear(), 0, 1).getTimezoneOffset() != date.getTimezoneOffset();
        },

        /**
         * Attempts to clear all time information from this Date by setting the time to midnight of the same day,
         * automatically adjusting for Daylight Saving Time (DST) where applicable.
         *
         * __Note:__ DST timezone information for the browser's host operating system is assumed to be up-to-date.
         * @param {Date} date The date
         * @param {Boolean} [clone=false] `true` to create a clone of this date, clear the time and return it.
         * @return {Date} this or the clone.
         */
        clearTime : function(date, clone) {
            if (clone) {
                return Ext.Date.clearTime(Ext.Date.clone(date));
            }

            // get current date before clearing time
            var d = date.getDate(),
                hr,
                c;

            // clear time
            date.setHours(0);
            date.setMinutes(0);
            date.setSeconds(0);
            date.setMilliseconds(0);

            if (date.getDate() != d) { // account for DST (i.e. day of month changed when setting hour = 0)
                // note: DST adjustments are assumed to occur in multiples of 1 hour (this is almost always the case)
                // refer to http://www.timeanddate.com/time/aboutdst.html for the (rare) exceptions to this rule

                // increment hour until cloned date == current date
                for (hr = 1, c = utilDate.add(date, Ext.Date.HOUR, hr); c.getDate() != d; hr++, c = utilDate.add(date, Ext.Date.HOUR, hr));

                date.setDate(d);
                date.setHours(c.getHours());
            }

            return date;
        },

        /**
         * Provides a convenient method for 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:
         *
         *     // Basic usage:
         *     var dt = Ext.Date.add(new Date('10/29/2006'), Ext.Date.DAY, 5);
         *     console.log(dt); // returns 'Fri Nov 03 2006 00:00:00'
         *
         *     // Negative values will be subtracted:
         *     var dt2 = Ext.Date.add(new Date('10/1/2006'), Ext.Date.DAY, -5);
         *     console.log(dt2); // returns 'Tue Sep 26 2006 00:00:00'
         *
         *      // Decimal values can be used:
         *     var dt3 = Ext.Date.add(new Date('10/1/2006'), Ext.Date.DAY, 1.25);
         *     console.log(dt3); // returns 'Mon Oct 02 2006 06:00:00'
         *
         * @param {Date} date The date to modify
         * @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(date, interval, value) {
            var d = Ext.Date.clone(date),
                Date = Ext.Date,
                day, decimalValue, base = 0;
            if (!interval || value === 0) {
                return d;
            }

            decimalValue = value - parseInt(value, 10);
            value = parseInt(value, 10);

            if (value) {
                switch(interval.toLowerCase()) {
                    // See EXTJSIV-7418. We use setTime() here to deal with issues related to
                    // the switchover that occurs when changing to daylight savings and vice
                    // versa. setTime() handles this correctly where setHour/Minute/Second/Millisecond
                    // do not. Let's assume the DST change occurs at 2am and we're incrementing using add
                    // for 15 minutes at time. When entering DST, we should see:
                    // 01:30am
                    // 01:45am
                    // 03:00am // skip 2am because the hour does not exist
                    // ...
                    // Similarly, leaving DST, we should see:
                    // 01:30am
                    // 01:45am
                    // 01:00am // repeat 1am because that's the change over
                    // 01:30am
                    // 01:45am
                    // 02:00am
                    // ....
                    //
                    case Ext.Date.MILLI:
                        d.setTime(d.getTime() + value);
                        break;
                    case Ext.Date.SECOND:
                        d.setTime(d.getTime() + value * 1000);
                        break;
                    case Ext.Date.MINUTE:
                        d.setTime(d.getTime() + value * 60 * 1000);
                        break;
                    case Ext.Date.HOUR:
                        d.setTime(d.getTime() + value * 60 * 60 * 1000);
                        break;
                    case Ext.Date.DAY:
                        d.setDate(d.getDate() + value);
                        break;
                    case Ext.Date.MONTH:
                        day = date.getDate();
                        if (day > 28) {
                            day = Math.min(day, Ext.Date.getLastDateOfMonth(Ext.Date.add(Ext.Date.getFirstDateOfMonth(date), Ext.Date.MONTH, value)).getDate());
                        }
                        d.setDate(day);
                        d.setMonth(date.getMonth() + value);
                        break;
                    case Ext.Date.YEAR:
                        day = date.getDate();
                        if (day > 28) {
                            day = Math.min(day, Ext.Date.getLastDateOfMonth(Ext.Date.add(Ext.Date.getFirstDateOfMonth(date), Ext.Date.YEAR, value)).getDate());
                        }
                        d.setDate(day);
                        d.setFullYear(date.getFullYear() + value);
                        break;
                }
            }

            if (decimalValue) {
                switch (interval.toLowerCase()) {
                    case Ext.Date.MILLI:    base = 1;               break;
                    case Ext.Date.SECOND:   base = 1000;            break;
                    case Ext.Date.MINUTE:   base = 1000*60;         break;
                    case Ext.Date.HOUR:     base = 1000*60*60;      break;
                    case Ext.Date.DAY:      base = 1000*60*60*24;   break;

                    case Ext.Date.MONTH:
                        day = utilDate.getDaysInMonth(d);
                        base = 1000*60*60*24*day;
                        break;

                    case Ext.Date.YEAR:
                        day = (utilDate.isLeapYear(d) ? 366 : 365);
                        base = 1000*60*60*24*day;
                        break;
                }
                if (base) {
                    d.setTime(d.getTime() + base * decimalValue);
                }
            }

            return d;
        },

        /**
         * Provides a convenient method for 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:
         *
         *     // Basic usage:
         *     var dt = Ext.Date.subtract(new Date('10/29/2006'), Ext.Date.DAY, 5);
         *     console.log(dt); // returns 'Tue Oct 24 2006 00:00:00'
         *
         *     // Negative values will be added:
         *     var dt2 = Ext.Date.subtract(new Date('10/1/2006'), Ext.Date.DAY, -5);
         *     console.log(dt2); // returns 'Fri Oct 6 2006 00:00:00'
         *
         *      // Decimal values can be used:
         *     var dt3 = Ext.Date.subtract(new Date('10/1/2006'), Ext.Date.DAY, 1.25);
         *     console.log(dt3); // returns 'Fri Sep 29 2006 06:00:00'
         *
         * @param {Date} date The date to modify
         * @param {String} interval A valid date interval enum value.
         * @param {Number} value The amount to subtract from the current date.
         * @return {Date} The new Date instance.
         */
        subtract: function(date, interval, value){
            return utilDate.add(date, interval, -value);
        },

        /**
         * Checks if a date falls on or between the given start and end dates.
         * @param {Date} date The date to check
         * @param {Date} start Start date
         * @param {Date} end End date
         * @return {Boolean} `true` if this date falls on or between the given start and end dates.
         */
        between : function(date, start, end) {
            var t = date.getTime();
            return start.getTime() <= t && t <= end.getTime();
        },

        //Maintains compatibility with old static and prototype window.Date methods.
        compat: function() {
            var nativeDate = window.Date,
                p,
                statics = ['useStrict', 'formatCodeToRegex', 'parseFunctions', 'parseRegexes', 'formatFunctions', 'y2kYear', 'MILLI', 'SECOND', 'MINUTE', 'HOUR', 'DAY', 'MONTH', 'YEAR', 'defaults', 'dayNames', 'monthNames', 'monthNumbers', 'getShortMonthName', 'getShortDayName', 'getMonthNumber', 'formatCodes', 'isValid', 'parseDate', 'getFormatCode', 'createFormat', 'createParser', 'parseCodes'],
                proto = ['dateFormat', 'format', 'getTimezone', 'getGMTOffset', 'getDayOfYear', 'getWeekOfYear', 'isLeapYear', 'getFirstDayOfMonth', 'getLastDayOfMonth', 'getDaysInMonth', 'getSuffix', 'clone', 'isDST', 'clearTime', 'add', 'between'],
                sLen    = statics.length,
                pLen    = proto.length,
                stat, prot, s;

            //Append statics
            for (s = 0; s < sLen; s++) {
                stat = statics[s];
                nativeDate[stat] = utilDate[stat];
            }

            //Append to prototype
            for (p = 0; p < pLen; p++) {
                prot = proto[p];
                nativeDate.prototype[prot] = function() {
                    var args = Array.prototype.slice.call(arguments);
                    args.unshift(this);
                    return utilDate[prot].apply(utilDate, args);
                };
            }
        }
      });
    };