moment.js

// moment.js
// version : 1.6.2
// author : Tim Wood
// license : MIT
// momentjs.com

(function (Date, undefined) {

    /************************************
        Constants
    ************************************/

    var moment,
        VERSION = "1.6.2",
        round = Math.round, i,
        // internal storage for language config files
        languages = {},
        currentLanguage = 'en',

        // check for nodeJS
        hasModule = (typeof module !== 'undefined'),

        // parameters to check for on the lang config
        langConfigProperties = 'months|monthsShort|monthsParse|weekdays|weekdaysShort|weekdaysMin|longDateFormat|calendar|relativeTime|ordinal|meridiem'.split('|'),

        // ASP.NET json date format regex
        aspNetJsonRegex = /^\/?Date\((\-?\d+)/i,

        // format tokens
        formattingTokens = /(\[[^\[]*\])|(\\)?(Mo|MM?M?M?|Do|DDDo|DD?D?D?|ddd?d?|do?|w[o|w]?|YYYY|YY|a|A|hh?|HH?|mm?|ss?|SS?S?|zz?|ZZ?)/g,
        localFormattingTokens = /(LT|LL?L?L?)/g,
        formattingRemoveEscapes = /(^\[)|(\\)|\]$/g,

        // parsing tokens
        parseMultipleFormatChunker = /([0-9a-zA-Z\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+)/gi,

        // parsing token regexes
        parseTokenOneOrTwoDigits = /\d\d?/, // 0 - 99
        parseTokenOneToThreeDigits = /\d{1,3}/, // 0 - 999
        parseTokenThreeDigits = /\d{3}/, // 000 - 999
        parseTokenFourDigits = /\d{4}/, // 0000 - 9999
        parseTokenWord = /[0-9a-z\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+/i, // any word characters or numbers
        parseTokenTimezone = /Z|[\+\-]\d\d:?\d\d/i, // +00:00 -00:00 +0000 -0000 or Z
        parseTokenT = /T/i, // T (ISO seperator)

        // preliminary iso regex 
        // 0000-00-00 + T + 00 or 00:00 or 00:00:00 or 00:00:00.000 + +00:00 or +0000
        isoRegex = /^\s*\d{4}-\d\d-\d\d(T(\d\d(:\d\d(:\d\d(\.\d\d?\d?)?)?)?)?([\+\-]\d\d:?\d\d)?)?/,
        isoFormat = 'YYYY-MM-DDTHH:mm:ssZ',

        // iso time formats and regexes
        isoTimes = [
            ['HH:mm:ss.S', /T\d\d:\d\d:\d\d\.\d{1,3}/],
            ['HH:mm:ss', /T\d\d:\d\d:\d\d/],
            ['HH:mm', /T\d\d:\d\d/],
            ['HH', /T\d\d/]
        ],

        // timezone chunker "+10:00" > ["10", "00"] or "-1530" > ["-15", "30"]
        parseTimezoneChunker = /([\+\-]|\d\d)/gi,

        // getter and setter names
        proxyGettersAndSetters = 'Month|Date|Hours|Minutes|Seconds|Milliseconds'.split('|'),
        unitMillisecondFactors = {
            'Milliseconds' : 1,
            'Seconds' : 1e3,
            'Minutes' : 6e4,
            'Hours' : 36e5,
            'Days' : 864e5,
            'Months' : 2592e6,
            'Years' : 31536e6
        },

        // format function strings
        formatFunctions = {},

        /*
         * moment.fn.format uses new Function() to create an inlined formatting function.
         * Results are a 3x speed boost
         * http://jsperf.com/momentjs-cached-format-functions
         *
         * These strings are appended into a function using replaceFormatTokens and makeFormatFunction
         */
        formatFunctionStrings = {
            // a = placeholder
            // b = placeholder
            // t = the current moment being formatted
            // v = getValueAtKey function
            // o = moment.ordinal function
            // p = leftZeroFill function
            // m = moment.meridiem value or function
            M    : '(a=t.month()+1)',
            MMM  : 'v("monthsShort",t.month())',
            MMMM : 'v("months",t.month())',
            D    : '(a=t.date())',
            DDD  : '(a=new Date(t.year(),t.month(),t.date()),b=new Date(t.year(),0,1),a=~~(((a-b)/864e5)+1.5))',
            d    : '(a=t.day())',
            dd   : 'v("weekdaysMin",t.day())',
            ddd  : 'v("weekdaysShort",t.day())',
            dddd : 'v("weekdays",t.day())',
            w    : '(a=new Date(t.year(),t.month(),t.date()-t.day()+5),b=new Date(a.getFullYear(),0,4),a=~~((a-b)/864e5/7+1.5))',
            YY   : 'p(t.year()%100,2)',
            YYYY : 't.year()',
            a    : 'm?m(t.hours(),t.minutes(),!1):t.hours()>11?"pm":"am"',
            A    : 'm?m(t.hours(),t.minutes(),!0):t.hours()>11?"PM":"AM"',
            H    : 't.hours()',
            h    : 't.hours()%12||12',
            m    : 't.minutes()',
            s    : 't.seconds()',
            S    : '~~(t.milliseconds()/100)',
            SS   : 'p(~~(t.milliseconds()/10),2)',
            SSS  : 'p(t.milliseconds(),3)',
            Z    : '((a=-t.zone())<0?((a=-a),"-"):"+")+p(~~(a/60),2)+":"+p(~~a%60,2)',
            ZZ   : '((a=-t.zone())<0?((a=-a),"-"):"+")+p(~~(10*a/6),4)'
        },

        ordinalizeTokens = 'DDD w M D d'.split(' '),
        paddedTokens = 'M D H h m s w'.split(' ');

    while (ordinalizeTokens.length) {
        i = ordinalizeTokens.pop();
        formatFunctionStrings[i + 'o'] = formatFunctionStrings[i] + '+o(a)';
    }
    while (paddedTokens.length) {
        i = paddedTokens.pop();
        formatFunctionStrings[i + i] = 'p(' + formatFunctionStrings[i] + ',2)';
    }
    formatFunctionStrings.DDDD = 'p(' + formatFunctionStrings.DDD + ',3)';


    /************************************
        Constructors
    ************************************/


    // Moment prototype object
    function Moment(date, isUTC) {
        this._d = date;
        this._isUTC = !!isUTC;
        if (date._a) {
            this._a = date._a;
            date._a = null;
            this._ac = (this._a[7] ? moment.utc(this) : this).toArray();
        }
    }

    // Duration Constructor
    function Duration(duration) {
        var data = this._data = {},
            years = duration.years || duration.y || 0,
            months = duration.months || duration.M || 0, 
            weeks = duration.weeks || duration.w || 0,
            days = duration.days || duration.d || 0,
            hours = duration.hours || duration.h || 0,
            minutes = duration.minutes || duration.m || 0,
            seconds = duration.seconds || duration.s || 0,
            milliseconds = duration.milliseconds || duration.ms || 0;

        // representation for dateAddRemove
        this._milliseconds = milliseconds +
            seconds * 1e3 + // 1000
            minutes * 6e4 + // 1000 * 60
            hours * 36e5; // 1000 * 60 * 60
        // Because of dateAddRemove treats 24 hours as different from a
        // day when working around DST, we need to store them separately
        this._days = days +
            weeks * 7;
        // It is impossible translate months into days without knowing
        // which months you are are talking about, so we have to store
        // it separately.
        this._months = months +
            years * 12;
            
        // The following code bubbles up values, see the tests for
        // examples of what that means.
        data.milliseconds = milliseconds % 1000;
        seconds += absRound(milliseconds / 1000);

        data.seconds = seconds % 60;
        minutes += absRound(seconds / 60);

        data.minutes = minutes % 60;
        hours += absRound(minutes / 60);

        data.hours = hours % 24;
        days += absRound(hours / 24);

        days += weeks * 7;
        data.days = days % 30;
        
        months += absRound(days / 30);

        data.months = months % 12;
        years += absRound(months / 12);

        data.years = years;
    }


    /************************************
        Helpers
    ************************************/


    function absRound(number) {
        if (number < 0) {
            return Math.ceil(number);
        } else {
            return Math.floor(number);
        }
    }

    // left zero fill a number
    // see http://jsperf.com/left-zero-filling for performance comparison
    function leftZeroFill(number, targetLength) {
        var output = number + '';
        while (output.length < targetLength) {
            output = '0' + output;
        }
        return output;
    }

    // helper function for _.addTime and _.subtractTime
    function addOrSubtractDurationFromMoment(mom, duration, isAdding) {
        var ms = duration._milliseconds,
            d = duration._days,
            M = duration._months,
            currentDate;

        if (ms) {
            mom._d.setTime(+mom + ms * isAdding);
        }
        if (d) {
            mom.date(mom.date() + d * isAdding);
        }
        if (M) {
            currentDate = mom.date();
            mom.date(1)
                .month(mom.month() + M * isAdding)
                .date(Math.min(currentDate, mom.daysInMonth()));
        }
    }

    // check if is an array
    function isArray(input) {
        return Object.prototype.toString.call(input) === '[object Array]';
    }

    // compare two arrays, return the number of differences
    function compareArrays(array1, array2) {
        var len = Math.min(array1.length, array2.length),
            lengthDiff = Math.abs(array1.length - array2.length),
            diffs = 0,
            i;
        for (i = 0; i < len; i++) {
            if (~~array1[i] !== ~~array2[i]) {
                diffs++;
            }
        }
        return diffs + lengthDiff;
    }

    // convert an array to a date.
    // the array should mirror the parameters below
    // note: all values past the year are optional and will default to the lowest possible value.
    // [year, month, day , hour, minute, second, millisecond]
    function dateFromArray(input, asUTC) {
        var i, date;
        for (i = 1; i < 7; i++) {
            input[i] = (input[i] == null) ? (i === 2 ? 1 : 0) : input[i];
        }
        // we store whether we used utc or not in the input array
        input[7] = asUTC;
        date = asUTC ? new Date(Date.UTC.apply({}, input)) :
            new Date(input[0], input[1], input[2], input[3], input[4], input[5], input[6]);
        date._a = input;
        return date;
    }


    /************************************
        Formatting
    ************************************/


    // helper for building inline formatting functions
    function replaceFormatTokens(token) {
        return formatFunctionStrings[token] ? 
            ("'+(" + formatFunctionStrings[token] + ")+'") :
            token.replace(formattingRemoveEscapes, "").replace(/\\?'/g, "\\'");
    }

    // helper for recursing long date formatting tokens
    function replaceLongDateFormatTokens(input) {
        return moment.longDateFormat[input] || input;
    }

    function makeFormatFunction(format) {
        var output = "var a,b;return '" +
            format.replace(formattingTokens, replaceFormatTokens) + "';",
            Fn = Function; // get around jshint
        // t = the current moment being formatted
        // v = getValueAtKey function
        // o = moment.ordinal function
        // p = leftZeroFill function
        // m = moment.meridiem value or function
        return new Fn('t', 'v', 'o', 'p', 'm', output);
    }

    function makeOrGetFormatFunction(format) {
        if (!formatFunctions[format]) {
            formatFunctions[format] = makeFormatFunction(format);
        }
        return formatFunctions[format];
    }

    // format date using native date object
    function formatMoment(m, format) {
        function getValueFromArray(key, index) {
            return moment[key].call ? moment[key](m, format) : moment[key][index];
        }

        while (localFormattingTokens.test(format)) {
            format = format.replace(localFormattingTokens, replaceLongDateFormatTokens);
        }

        if (!formatFunctions[format]) {
            formatFunctions[format] = makeFormatFunction(format);
        }

        return formatFunctions[format](m, getValueFromArray, moment.ordinal, leftZeroFill, moment.meridiem);
    }


    /************************************
        Parsing
    ************************************/


    // get the regex to find the next token
    function getParseRegexForToken(token) {
        switch (token) {
        case 'DDDD':
            return parseTokenThreeDigits;
        case 'YYYY':
            return parseTokenFourDigits;
        case 'S':
        case 'SS':
        case 'SSS':
        case 'DDD':
            return parseTokenOneToThreeDigits;
        case 'MMM':
        case 'MMMM':
        case 'dd':
        case 'ddd':
        case 'dddd':
        case 'a':
        case 'A':
            return parseTokenWord;
        case 'Z':
        case 'ZZ':
            return parseTokenTimezone;
        case 'T':
            return parseTokenT;
        case 'MM':
        case 'DD':
        case 'YY':
        case 'HH':
        case 'hh':
        case 'mm':
        case 'ss':
        case 'M':
        case 'D':
        case 'd':
        case 'H':
        case 'h':
        case 'm':
        case 's':
            return parseTokenOneOrTwoDigits;
        default :
            return new RegExp(token.replace('\\', ''));
        }
    }

    // function to convert string input to date
    function addTimeToArrayFromToken(token, input, datePartArray, config) {
        var a;
        //console.log('addTime', format, input);
        switch (token) {
        // MONTH
        case 'M' : // fall through to MM
        case 'MM' :
            datePartArray[1] = (input == null) ? 0 : ~~input - 1;
            break;
        case 'MMM' : // fall through to MMMM
        case 'MMMM' :
            for (a = 0; a < 12; a++) {
                if (moment.monthsParse[a].test(input)) {
                    datePartArray[1] = a;
                    break;
                }
            }
            break;
        // DAY OF MONTH
        case 'D' : // fall through to DDDD
        case 'DD' : // fall through to DDDD
        case 'DDD' : // fall through to DDDD
        case 'DDDD' :
            if (input != null) {
                datePartArray[2] = ~~input;
            }
            break;
        // YEAR
        case 'YY' :
            input = ~~input;
            datePartArray[0] = input + (input > 70 ? 1900 : 2000);
            break;
        case 'YYYY' :
            datePartArray[0] = ~~Math.abs(input);
            break;
        // AM / PM
        case 'a' : // fall through to A
        case 'A' :
            config.isPm = ((input + '').toLowerCase() === 'pm');
            break;
        // 24 HOUR
        case 'H' : // fall through to hh
        case 'HH' : // fall through to hh
        case 'h' : // fall through to hh
        case 'hh' :
            datePartArray[3] = ~~input;
            break;
        // MINUTE
        case 'm' : // fall through to mm
        case 'mm' :
            datePartArray[4] = ~~input;
            break;
        // SECOND
        case 's' : // fall through to ss
        case 'ss' :
            datePartArray[5] = ~~input;
            break;
        // MILLISECOND
        case 'S' :
        case 'SS' :
        case 'SSS' :
            datePartArray[6] = ~~ (('0.' + input) * 1000);
            break;
        // TIMEZONE
        case 'Z' : // fall through to ZZ
        case 'ZZ' :
            config.isUTC = true;
            a = (input + '').match(parseTimezoneChunker);
            if (a && a[1]) {
                config.tzh = ~~a[1];
            }
            if (a && a[2]) {
                config.tzm = ~~a[2];
            }
            // reverse offsets
            if (a && a[0] === '+') {
                config.tzh = -config.tzh;
                config.tzm = -config.tzm;
            }
            break;
        }
    }

    // date from string and format string
    function makeDateFromStringAndFormat(string, format) {
        var datePartArray = [0, 0, 1, 0, 0, 0, 0],
            config = {
                tzh : 0, // timezone hour offset
                tzm : 0  // timezone minute offset
            },
            tokens = format.match(formattingTokens),
            i, parsedInput;

        for (i = 0; i < tokens.length; i++) {
            parsedInput = (getParseRegexForToken(tokens[i]).exec(string) || [])[0];
            string = string.replace(getParseRegexForToken(tokens[i]), '');
            addTimeToArrayFromToken(tokens[i], parsedInput, datePartArray, config);
        }
        // handle am pm
        if (config.isPm && datePartArray[3] < 12) {
            datePartArray[3] += 12;
        }
        // if is 12 am, change hours to 0
        if (config.isPm === false && datePartArray[3] === 12) {
            datePartArray[3] = 0;
        }
        // handle timezone
        datePartArray[3] += config.tzh;
        datePartArray[4] += config.tzm;
        // return
        return dateFromArray(datePartArray, config.isUTC);
    }

    // date from string and array of format strings
    function makeDateFromStringAndArray(string, formats) {
        var output,
            inputParts = string.match(parseMultipleFormatChunker) || [],
            formattedInputParts,
            scoreToBeat = 99,
            i,
            currentDate,
            currentScore;
        for (i = 0; i < formats.length; i++) {
            currentDate = makeDateFromStringAndFormat(string, formats[i]);
            formattedInputParts = formatMoment(new Moment(currentDate), formats[i]).match(parseMultipleFormatChunker) || [];
            currentScore = compareArrays(inputParts, formattedInputParts);
            if (currentScore < scoreToBeat) {
                scoreToBeat = currentScore;
                output = currentDate;
            }
        }
        return output;
    }

    // date from iso format
    function makeDateFromString(string) {
        var format = 'YYYY-MM-DDT',
            i;
        if (isoRegex.exec(string)) {
            for (i = 0; i < 4; i++) {
                if (isoTimes[i][1].exec(string)) {
                    format += isoTimes[i][0];
                    break;
                }
            }
            return parseTokenTimezone.exec(string) ? 
                makeDateFromStringAndFormat(string, format + ' Z') :
                makeDateFromStringAndFormat(string, format);
        }
        return new Date(string);
    }


    /************************************
        Relative Time
    ************************************/


    // helper function for moment.fn.from, moment.fn.fromNow, and moment.duration.fn.humanize
    function substituteTimeAgo(string, number, withoutSuffix, isFuture) {
        var rt = moment.relativeTime[string];
        return (typeof rt === 'function') ?
            rt(number || 1, !!withoutSuffix, string, isFuture) :
            rt.replace(/%d/i, number || 1);
    }

    function relativeTime(milliseconds, withoutSuffix) {
        var seconds = round(Math.abs(milliseconds) / 1000),
            minutes = round(seconds / 60),
            hours = round(minutes / 60),
            days = round(hours / 24),
            years = round(days / 365),
            args = seconds < 45 && ['s', seconds] ||
                minutes === 1 && ['m'] ||
                minutes < 45 && ['mm', minutes] ||
                hours === 1 && ['h'] ||
                hours < 22 && ['hh', hours] ||
                days === 1 && ['d'] ||
                days <= 25 && ['dd', days] ||
                days <= 45 && ['M'] ||
                days < 345 && ['MM', round(days / 30)] ||
                years === 1 && ['y'] || ['yy', years];
        args[2] = withoutSuffix;
        args[3] = milliseconds > 0;
        return substituteTimeAgo.apply({}, args);
    }


    /************************************
        Top Level Functions
    ************************************/


    moment = function (input, format) {
        if (input === null || input === '') {
            return null;
        }
        var date,
            matched,
            isUTC;
        // parse Moment object
        if (moment.isMoment(input)) {
            date = new Date(+input._d);
            isUTC = input._isUTC;
        // parse string and format
        } else if (format) {
            if (isArray(format)) {
                date = makeDateFromStringAndArray(input, format);
            } else {
                date = makeDateFromStringAndFormat(input, format);
            }
        // evaluate it as a JSON-encoded date
        } else {
            matched = aspNetJsonRegex.exec(input);
            date = input === undefined ? new Date() :
                matched ? new Date(+matched[1]) :
                input instanceof Date ? input :
                isArray(input) ? dateFromArray(input) :
                typeof input === 'string' ? makeDateFromString(input) :
                new Date(input);
        }
        return new Moment(date, isUTC);
    };

    // creating with utc
    moment.utc = function (input, format) {
        if (isArray(input)) {
            return new Moment(dateFromArray(input, true), true);
        }
        return (format && input) ?
            moment(input + ' +0000', format + ' Z').utc() :
            moment(input && isoRegex.exec(input) && !parseTokenTimezone.exec(input) ? input + '+0000' : input).utc();
    };

    // creating with unix timestamp (in seconds)
    moment.unix = function (input) {
        return moment(input * 1000);
    };

    // duration
    moment.duration = function (input, key) {
        var isDuration = moment.isDuration(input),
            isNumber = (typeof input === 'number'),
            duration = (isDuration ? input._data : (isNumber ? {} : input));

        if (isNumber) {
            if (key) {
                duration[key] = input;
            } else {
                duration.milliseconds = input;
            }
        }

        return new Duration(duration);
    };

    // humanizeDuration
    // This method is deprecated in favor of the new Duration object.  Please
    // see the moment.duration method.
    moment.humanizeDuration = function (num, type, withSuffix) {
        return moment.duration(num, type === true ? null : type).humanize(type === true ? true : withSuffix);
    };

    // version number
    moment.version = VERSION;

    // default format
    moment.defaultFormat = isoFormat;

    // language switching and caching
    moment.lang = function (key, values) {
        var i, req,
            parse = [];
        if (!key) {
            return currentLanguage;
        }
        if (values) {
            for (i = 0; i < 12; i++) {
                parse[i] = new RegExp('^' + values.months[i] + '|^' + values.monthsShort[i].replace('.', ''), 'i');
            }
            values.monthsParse = values.monthsParse || parse;
            languages[key] = values;
        }
        if (languages[key]) {
            for (i = 0; i < langConfigProperties.length; i++) {
                moment[langConfigProperties[i]] = languages[key][langConfigProperties[i]] || 
                    languages.en[langConfigProperties[i]];
            }
            currentLanguage = key;
        } else {
            if (hasModule) {
                req = require('./lang/' + key);
                moment.lang(key, req);
            }
        }
    };

    // set default language
    moment.lang('en', {
        months : "January_February_March_April_May_June_July_August_September_October_November_December".split("_"),
        monthsShort : "Jan_Feb_Mar_Apr_May_Jun_Jul_Aug_Sep_Oct_Nov_Dec".split("_"),
        weekdays : "Sunday_Monday_Tuesday_Wednesday_Thursday_Friday_Saturday".split("_"),
        weekdaysShort : "Sun_Mon_Tue_Wed_Thu_Fri_Sat".split("_"),
        weekdaysMin : "Su_Mo_Tu_We_Th_Fr_Sa".split("_"),
        longDateFormat : {
            LT : "h:mm A",
            L : "MM/DD/YYYY",
            LL : "MMMM D YYYY",
            LLL : "MMMM D YYYY LT",
            LLLL : "dddd, MMMM D YYYY LT"
        },
        meridiem : false,
        calendar : {
            sameDay : '[Today at] LT',
            nextDay : '[Tomorrow at] LT',
            nextWeek : 'dddd [at] LT',
            lastDay : '[Yesterday at] LT',
            lastWeek : '[last] dddd [at] LT',
            sameElse : 'L'
        },
        relativeTime : {
            future : "in %s",
            past : "%s ago",
            s : "a few seconds",
            m : "a minute",
            mm : "%d minutes",
            h : "an hour",
            hh : "%d hours",
            d : "a day",
            dd : "%d days",
            M : "a month",
            MM : "%d months",
            y : "a year",
            yy : "%d years"
        },
        ordinal : function (number) {
            var b = number % 10;
            return (~~ (number % 100 / 10) === 1) ? 'th' :
                (b === 1) ? 'st' :
                (b === 2) ? 'nd' :
                (b === 3) ? 'rd' : 'th';
        }
    });

    // compare moment object
    moment.isMoment = function (obj) {
        return obj instanceof Moment;
    };

    // for typechecking Duration objects
    moment.isDuration = function (obj) {
        return obj instanceof Duration;
    };


    /************************************
        Moment Prototype
    ************************************/


    moment.fn = Moment.prototype = {

        clone : function () {
            return moment(this);
        },

        valueOf : function () {
            return +this._d;
        },

        unix : function () {
            return Math.floor(+this._d / 1000);
        },

        toString : function () {
            return this._d.toString();
        },

        toDate : function () {
            return this._d;
        },

        toArray : function () {
            var m = this;
            return [
                m.year(),
                m.month(),
                m.date(),
                m.hours(),
                m.minutes(),
                m.seconds(),
                m.milliseconds(),
                !!this._isUTC
            ];
        },

        isValid : function () {
            if (this._a && this._ac) {
                return !compareArrays(this._a, this._ac);
            }
            return !isNaN(this._d.getTime());
        },

        utc : function () {
            this._isUTC = true;
            return this;
        },

        local : function () {
            this._isUTC = false;
            return this;
        },

        format : function (inputString) {
            return formatMoment(this, inputString ? inputString : moment.defaultFormat);
        },

        add : function (input, val) {
            var dur = val ? moment.duration(+val, input) : moment.duration(input);
            addOrSubtractDurationFromMoment(this, dur, 1);
            return this;
        },

        subtract : function (input, val) {
            var dur = val ? moment.duration(+val, input) : moment.duration(input);
            addOrSubtractDurationFromMoment(this, dur, -1);
            return this;
        },

        diff : function (input, val, asFloat) {
            var inputMoment = this._isUTC ? moment(input).utc() : moment(input).local(),
                zoneDiff = (this.zone() - inputMoment.zone()) * 6e4,
                diff = this._d - inputMoment._d - zoneDiff,
                year = this.year() - inputMoment.year(),
                month = this.month() - inputMoment.month(),
                date = this.date() - inputMoment.date(),
                output;
            if (val === 'months') {
                output = year * 12 + month + date / 30;
            } else if (val === 'years') {
                output = year + (month + date / 30) / 12;
            } else {
                output = val === 'seconds' ? diff / 1e3 : // 1000
                    val === 'minutes' ? diff / 6e4 : // 1000 * 60
                    val === 'hours' ? diff / 36e5 : // 1000 * 60 * 60
                    val === 'days' ? diff / 864e5 : // 1000 * 60 * 60 * 24
                    val === 'weeks' ? diff / 6048e5 : // 1000 * 60 * 60 * 24 * 7
                    diff;
            }
            return asFloat ? output : round(output);
        },

        from : function (time, withoutSuffix) {
            return moment.duration(this.diff(time)).humanize(!withoutSuffix);
        },

        fromNow : function (withoutSuffix) {
            return this.from(moment(), withoutSuffix);
        },

        calendar : function () {
            var diff = this.diff(moment().sod(), 'days', true),
                calendar = moment.calendar,
                allElse = calendar.sameElse,
                format = diff < -6 ? allElse :
                diff < -1 ? calendar.lastWeek :
                diff < 0 ? calendar.lastDay :
                diff < 1 ? calendar.sameDay :
                diff < 2 ? calendar.nextDay :
                diff < 7 ? calendar.nextWeek : allElse;
            return this.format(typeof format === 'function' ? format.apply(this) : format);
        },

        isLeapYear : function () {
            var year = this.year();
            return (year % 4 === 0 && year % 100 !== 0) || year % 400 === 0;
        },

        isDST : function () {
            return (this.zone() < moment([this.year()]).zone() || 
                this.zone() < moment([this.year(), 5]).zone());
        },

        day : function (input) {
            var day = this._isUTC ? this._d.getUTCDay() : this._d.getDay();
            return input == null ? day :
                this.add({ d : input - day });
        },

        startOf: function (val) {
            var output = this.clone();
            // the following switch intentionally omits break keywords
            // to utilize falling through the cases.
            switch (val) {
            case 'year':
                output.month(0);
                /* falls through */
            case 'month':
                output.date(1);
                /* falls through */
            case 'day':
                output.hours(0);
                /* falls through */
            case 'hour':
                output.minutes(0);
                /* falls through */
            case 'minute':
                output.seconds(0);
                /* falls through */
            case 'second':
                output.milliseconds(0);
                /* falls through */
            }
            return output;
        },
                
        endOf: function (val) {
            return this.startOf(val).add(val + 's', 1).subtract('milliseconds', 1);
        },
        
        sod: function () {
            return this.startOf('day');
        },

        eod: function () {
            // end of day = start of day plus 1 day, minus 1 millisecond
            return this.endOf('day');
        },

        zone : function () {
            return this._isUTC ? 0 : this._d.getTimezoneOffset();
        },

        daysInMonth : function () {
            return moment.utc([this.year(), this.month() + 1, 0]).date();
        }
    };

    // helper for adding shortcuts
    function makeGetterAndSetter(name, key) {
        moment.fn[name] = function (input) {
            var utc = this._isUTC ? 'UTC' : '';
            if (input != null) {
                this._d['set' + utc + key](input);
                return this;
            } else {
                return this._d['get' + utc + key]();
            }
        };
    }

    // loop through and add shortcuts (Month, Date, Hours, Minutes, Seconds, Milliseconds)
    for (i = 0; i < proxyGettersAndSetters.length; i ++) {
        makeGetterAndSetter(proxyGettersAndSetters[i].toLowerCase(), proxyGettersAndSetters[i]);
    }

    // add shortcut for year (uses different syntax than the getter/setter 'year' == 'FullYear')
    makeGetterAndSetter('year', 'FullYear');


    /************************************
        Duration Prototype
    ************************************/


    moment.duration.fn = Duration.prototype = {
        weeks : function () {
            return absRound(this.days() / 7);
        },

        valueOf : function () {
            return this._milliseconds +
              this._days * 864e5 +
              this._months * 2592e6;
        },

        humanize : function (withSuffix) {
            var difference = +this,
                rel = moment.relativeTime,
                output = relativeTime(difference, !withSuffix);

            if (withSuffix) {
                output = (difference <= 0 ? rel.past : rel.future).replace(/%s/i, output);
            }

            return output;
        }
    };

    function makeDurationGetter(name) {
        moment.duration.fn[name] = function () {
            return this._data[name];
        };
    }

    function makeDurationAsGetter(name, factor) {
        moment.duration.fn['as' + name] = function () {
            return +this / factor;
        };
    }

    for (i in unitMillisecondFactors) {
        if (unitMillisecondFactors.hasOwnProperty(i)) {
            makeDurationAsGetter(i, unitMillisecondFactors[i]);
            makeDurationGetter(i.toLowerCase());
        }
    }

    makeDurationAsGetter('Weeks', 6048e5);


    /************************************
        Exposing Moment
    ************************************/


    // CommonJS module is defined
    if (hasModule) {
        module.exports = moment;
    }
    /*global ender:false */
    if (typeof window !== 'undefined' && typeof ender === 'undefined') {
        window.moment = moment;
    }
    /*global define:false */
    if (typeof define === "function" && define.amd) {
        define("moment", [], function () {
            return moment;
        });
    }
})(Date);