date.js

ext-2.3.0

    },

    /**
     * Get the numeric ISO-8601 week number of the year.
     * (equivalent to the format specifier 'W', but without a leading zero).
     * @return {Number} 1 to 53
     */
    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() { // return a closure so constants get calculated only once
            var DC3 = Date.UTC(this.getFullYear(), this.getMonth(), this.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.
     * @return {Boolean} True if the current date falls within a leap year, false otherwise.
     */
    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() {
        return this.getLastDateOfMonth().getDay();
    },


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

    /**
     * Get the date of the last day of the month in which this date resides.
     * @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() {
        var daysInMonth = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];

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

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

    /**
     * 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());
    },

    /**
     * Checks if the current date is affected by Daylight Saving Time (DST).
     * @return {Boolean} True if the current date is affected by DST.
     */
    isDST : function() {
        // adapted from http://extjs.com/forum/showthread.php?p=247172#post247172
        // courtesy of @geoffrey.mcgill
        return new Date(this.getFullYear(), 0, 1).getTimezoneOffset() != this.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 {Boolean} clone true to create a clone of this date, clear the time and return it (defaults to false).
     * @return {Date} this or the clone.
     */
    clearTime : function(clone) {
        if (clone) {
            return this.clone().clearTime();
        }

        // get current date before clearing time
        var d = this.getDate();

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

        if (this.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 (var hr = 1, c = this.add(Date.HOUR, hr); c.getDate() != d; hr++, c = this.add(Date.HOUR, hr));

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

        return this;
    },

    /**
     * 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:
     * <pre><code>
// Basic usage:
var dt = new Date('10/29/2006').add(Date.DAY, 5);
document.write(dt); //returns 'Fri Nov 03 2006 00:00:00'

// Negative values will be subtracted:
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;
    },

    /**
     * Checks if this date falls on or between the given start and end dates.
     * @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(start, end) {
        var t = this.getTime();
        return start.getTime() <= t && t <= end.getTime();
    }
});


/**
 * Formats a date given the supplied format string.
 * @param {String} format The format string.
 * @return {String} The formatted date.
 * @method format
 */
Date.prototype.format = Date.prototype.dateFormat;


// private
if (Ext.isSafari && (navigator.userAgent.match(/WebKit\/(\d+)/)[1] || NaN) < 420) {
    Ext.apply(Date.prototype, {
        _xMonth : Date.prototype.setMonth,
        _xDate  : Date.prototype.setDate,

        // Bug in Safari 1.3, 2.0 (WebKit build < 420)
        // Date.setMonth does not work consistently if iMonth is not 0-11
        setMonth : function(num) {
            if (num <= -1) {
                var n = Math.ceil(-num),
                    back_year = Math.ceil(n / 12),
                    month = (n % 12) ? 12 - n % 12 : 0;

                this.setFullYear(this.getFullYear() - back_year);

                return this._xMonth(month);
            } else {
                return this._xMonth(num);
            }
        },

        // Bug in setDate() method (resolved in WebKit build 419.3, so to be safe we target Webkit builds < 420)
        // The parameter for Date.setDate() is converted to a signed byte integer in Safari
        // http://brianary.blogspot.com/2006/03/safari-date-bug.html
        setDate : function(d) {
            // use setTime() to workaround setDate() bug
            // subtract current day of month in milliseconds, then add desired day of month in milliseconds
            return this.setTime(this.getTime() - (this.getDate() - d) * 864e5);
        }
    });
}



/* Some basic Date tests... (requires Firebug)

Date.parseDate('', 'c'); // call Date.parseDate() once to force computation of regex string so we can console.log() it
console.log('Insane Regex for "c" format: %o', Date.parseCodes.c.s); // view the insane regex for the "c" format specifier

// standard tests
console.group('Standard Date.parseDate() Tests');
    console.log('Date.parseDate("2009-01-05T11:38:56", "c")               = %o', Date.parseDate("2009-01-05T11:38:56", "c")); // assumes browser's timezone setting
    console.log('Date.parseDate("2009-02-04T12:37:55.001000", "c")        = %o', Date.parseDate("2009-02-04T12:37:55.001000", "c")); // assumes browser's timezone setting
    console.log('Date.parseDate("2009-03-03T13:36:54,101000Z", "c")       = %o', Date.parseDate("2009-03-03T13:36:54,101000Z", "c")); // UTC
    console.log('Date.parseDate("2009-04-02T14:35:53.901000-0530", "c")   = %o', Date.parseDate("2009-04-02T14:35:53.901000-0530", "c")); // GMT-0530
    console.log('Date.parseDate("2009-05-01T15:34:52,9876000+08:00", "c") = %o', Date.parseDate("2009-05-01T15:34:52,987600+08:00", "c")); // GMT+08:00
console.groupEnd();

// ISO-8601 format as specified in http://www.w3.org/TR/NOTE-datetime
// -- accepts ALL 6 levels of date-time granularity
console.group('ISO-8601 Granularity Test (see http://www.w3.org/TR/NOTE-datetime)');
    console.log('Date.parseDate("1997", "c")                              = %o', Date.parseDate("1997", "c")); // YYYY (eg 1997)
    console.log('Date.parseDate("1997-07", "c")                           = %o', Date.parseDate("1997-07", "c")); // YYYY-MM (eg 1997-07)
    console.log('Date.parseDate("1997-07-16", "c")                        = %o', Date.parseDate("1997-07-16", "c")); // YYYY-MM-DD (eg 1997-07-16)
    console.log('Date.parseDate("1997-07-16T19:20+01:00", "c")            = %o', Date.parseDate("1997-07-16T19:20+01:00", "c")); // YYYY-MM-DDThh:mmTZD (eg 1997-07-16T19:20+01:00)
    console.log('Date.parseDate("1997-07-16T19:20:30+01:00", "c")         = %o', Date.parseDate("1997-07-16T19:20:30+01:00", "c")); // YYYY-MM-DDThh:mm:ssTZD (eg 1997-07-16T19:20:30+01:00)
    console.log('Date.parseDate("1997-07-16T19:20:30.45+01:00", "c")      = %o', Date.parseDate("1997-07-16T19:20:30.45+01:00", "c")); // YYYY-MM-DDThh:mm:ss.sTZD (eg 1997-07-16T19:20:30.45+01:00)
    console.log('Date.parseDate("1997-07-16 19:20:30.45+01:00", "c")      = %o', Date.parseDate("1997-07-16 19:20:30.45+01:00", "c")); // YYYY-MM-DD hh:mm:ss.sTZD (eg 1997-07-16T19:20:30.45+01:00)
    console.log('Date.parseDate("1997-13-16T19:20:30.45+01:00", "c", true)= %o', Date.parseDate("1997-13-16T19:20:30.45+01:00", "c", true)); // strict date parsing with invalid month value
console.groupEnd();

//*/