Compare dates with javascript

Question

I have two dates in javascript:

var first = '2012-11-21';
var second = '2012-11-03';

i would like make:

 if(first > second){
   //...
 }

how is the best way for this, without external library?

not a possible duplicate, an exact duplicate - even the titles are the same :) (Do people ever Google before asking questions?) — Dvir, Jun 23 '12 at 14:00
@DvirAzulay - It's _not_ an exact duplicate: this one shows enough code to imply that strings with a specific date format will be used (which, as explained in my answer, requires _no conversion_ in order to compare), but the other question gives no information about format. — nnnnnn, Jun 23 '12 at 14:21

score 61 · Accepted Answer · answered Jun 23 '12 at 13:57

61

if( (new Date(first).getTime() > new Date(second).getTime()))
{
    ----------------------------------
}

answered Jun 23 '12 at 13:57

Arthur Neves

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1

too much work, 2 new Date object, and 3 times multiplication, and compare it. – totten Jun 23 '12 at 14:17
It's not working on dd/mm/yyyy format, So it need to convert to either mm/dd/yyyy or yyyy/mm/dd – Ronak Patel Jun 18 '15 at 13:36
It will work without calling getTime() method. – Iván Rodríguez Torres Jan 13 '16 at 13:50
This is great, it allowed me to compare dates by attaching .getTime() to date objects that I turned into strings with toUTCString(), haven't been able to compare dates that were converted into strings in the past, so that was a nice surprise! – iPzard Jun 14 '18 at 01:07

score 16 · Answer 2 · answered Jun 23 '12 at 14:16

16

If your dates are strings in a strict yyyy-mm-dd format as shown in the question then your code will work as is without converting to date objects or numbers:

if(first > second){

...will do a lexographic (i.e., alphanumeric "dictionary order") string comparison - which will compare the first characters of each string, then the second characters of each string, etc. Which will give the result you want...

answered Jun 23 '12 at 14:16

nnnnnn

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This is the most sensible answer I've seen, should get more upvotes – Romuald Brunet Dec 17 '20 at 22:03

score 8 · Answer 3 · edited Jun 05 '17 at 11:13

8

You can do this way, it will work fine:

var date1 = new Date('2013-07-30');
var date2 = new Date('2013-07-30');

if(date1 === date2){ console.log("both are equal");}  //it does not work 
==>undefined  //result
if(+date1 === +date2){ console.log("both are equal");} //do it this way! 
//(use + prefix for a variable that holds a date value)
==> both are equal //result

Note :- don't forget to use a + prefix

edited Jun 05 '17 at 11:13

KP Chundawat

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answered Jul 30 '13 at 09:00

Balachandar1887229

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Works in IE. Having problems getting this to work in Chrome. IE date comes from a textbox. Chrome comes from a date picker. – Sam Jun 26 '18 at 19:07

score 5 · Answer 4 · edited Jan 15 '14 at 15:36

5

The best way is,

var first = '2012-11-21';
var second = '2012-11-03';

if (new Date(first) > new Date(second) {
    .....
}

edited Jan 15 '14 at 15:36

Deepak Ingole

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answered Aug 06 '13 at 11:41

MICHAEL PRABHU

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totten · Answer 5 · 2012-06-23T14:12:34.307

4

Because of your date format, you can use this code:

if(parseInt(first.replace(/-/g,""),10) > parseInt(second.replace(/-/g,""),10)){
   //...
}

It will check whether 20121121 number is bigger than 20121103 or not.

edited Jun 23 '12 at 14:12

answered Jun 23 '12 at 14:03

totten

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Nope, it won't work. `replace` will replace only the first occurrence of dash. – VisioN Jun 23 '12 at 14:08
Sure, I edited and tested it, It's now working :) – totten Jun 23 '12 at 14:13
If that date format can be counted on then (as per my answer) you can just compare them as strings, no conversion necessary... – nnnnnn Jun 23 '12 at 14:23
He may have 2012-11-3, think about that :) – totten Jun 23 '12 at 14:24
1

That's why I said "if that date format can be counted on". If not, then neither of our answers would work with single-digit months. If the data is entered by the user none of the answers (so far) would be reliable... – nnnnnn Jun 23 '12 at 14:27
ah, yes you're right. I can split the date but it's not neccesary for such a comparison. – totten Jun 23 '12 at 14:29
You comment on the other answer "Too much work", yet yourself rely on regular expressions? – Sebastian Mach Oct 28 '14 at 07:05

score 2 · Answer 6 · answered Apr 03 '13 at 10:47

USe this function for date comparison in javascript:

    function fn_DateCompare(DateA, DateB) {
      var a = new Date(DateA);
      var b = new Date(DateB);

      var msDateA = Date.UTC(a.getFullYear(), a.getMonth()+1, a.getDate());
      var msDateB = Date.UTC(b.getFullYear(), b.getMonth()+1, b.getDate());

      if (parseFloat(msDateA) < parseFloat(msDateB))
        return -1;  // less than
      else if (parseFloat(msDateA) == parseFloat(msDateB))
        return 0;  // equal
      else if (parseFloat(msDateA) > parseFloat(msDateB))
        return 1;  // greater than
      else
        return null;  // error
  }

Nimesh Vaghasiya · Answer 7 · 2013-12-20T04:40:09.497

you can done this way also.

if (dateFormat(first, "yyyy-mm-dd") > dateFormat(second, "yyyy-mm-dd")) {
        console.log("done");
}

OR

if (dateFormat(first, "mm-dd-yyyy") >  dateFormat(second, "mm-dd-yyyy")) {
        console.log("done");
}

i use following plugin for dateFormat()

        var dateFormat = function () {
        var token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZ]|"[^"]*"|'[^']*'/g,
            timezone = /\b(?:[PMCEA][SDP]T|(?:Pacific|Mountain|Central|Eastern|Atlantic) (?:Standard|Daylight|Prevailing) Time|(?:GMT|UTC)(?:[-+]\d{4})?)\b/g,
            timezoneClip = /[^-+\dA-Z]/g,
            pad = function (val, len) {
                val = String(val);
                len = len || 2;
                while (val.length < len) val = "0" + val;
                return val;
            };

        // Regexes and supporting functions are cached through closure
        return function (date, mask, utc) {
            var dF = dateFormat;

            // You can't provide utc if you skip other args (use the "UTC:" mask prefix)
            if (arguments.length == 1 && Object.prototype.toString.call(date) == "[object String]" && !/\d/.test(date)) {
                mask = date;
                date = undefined;
            }

            // Passing date through Date applies Date.parse, if necessary
            date = date ? new Date(date) : new Date;
            if (isNaN(date)) throw SyntaxError("invalid date");

            mask = String(dF.masks[mask] || mask || dF.masks["default"]);

            // Allow setting the utc argument via the mask
            if (mask.slice(0, 4) == "UTC:") {
                mask = mask.slice(4);
                utc = true;
            }

            var _ = utc ? "getUTC" : "get",
                d = date[_ + "Date"](),
                D = date[_ + "Day"](),
                m = date[_ + "Month"](),
                y = date[_ + "FullYear"](),
                H = date[_ + "Hours"](),
                M = date[_ + "Minutes"](),
                s = date[_ + "Seconds"](),
                L = date[_ + "Milliseconds"](),
                o = utc ? 0 : date.getTimezoneOffset(),
                flags = {
                    d:    d,
                    dd:   pad(d),
                    ddd:  dF.i18n.dayNames[D],
                    dddd: dF.i18n.dayNames[D + 7],
                    m:    m + 1,
                    mm:   pad(m + 1),
                    mmm:  dF.i18n.monthNames[m],
                    mmmm: dF.i18n.monthNames[m + 12],
                    yy:   String(y).slice(2),
                    yyyy: y,
                    h:    H % 12 || 12,
                    hh:   pad(H % 12 || 12),
                    H:    H,
                    HH:   pad(H),
                    M:    M,
                    MM:   pad(M),
                    s:    s,
                    ss:   pad(s),
                    l:    pad(L, 3),
                    L:    pad(L > 99 ? Math.round(L / 10) : L),
                    t:    H < 12 ? "a"  : "p",
                    tt:   H < 12 ? "am" : "pm",
                    T:    H < 12 ? "A"  : "P",
                    TT:   H < 12 ? "AM" : "PM",
                    Z:    utc ? "UTC" : (String(date).match(timezone) || [""]).pop().replace(timezoneClip, ""),
                    o:    (o > 0 ? "-" : "+") + pad(Math.floor(Math.abs(o) / 60) * 100 + Math.abs(o) % 60, 4),
                    S:    ["th", "st", "nd", "rd"][d % 10 > 3 ? 0 : (d % 100 - d % 10 != 10) * d % 10]
                };

            return mask.replace(token, function ($0) {
                return $0 in flags ? flags[$0] : $0.slice(1, $0.length - 1);
            });
        };
    }();

    // Some common format strings
    dateFormat.masks = {
        "default":      "ddd mmm dd yyyy HH:MM:ss",
        shortDate:      "m/d/yy",
        mediumDate:     "mmm d, yyyy",
        longDate:       "mmmm d, yyyy",
        fullDate:       "dddd, mmmm d, yyyy",
        shortTime:      "h:MM TT",
        mediumTime:     "h:MM:ss TT",
        longTime:       "h:MM:ss TT Z",
        isoDate:        "yyyy-mm-dd",
        isoTime:        "HH:MM:ss",
        isoDateTime:    "yyyy-mm-dd'T'HH:MM:ss",
        isoUtcDateTime: "UTC:yyyy-mm-dd'T'HH:MM:ss'Z'"
    };

    // Internationalization strings
    dateFormat.i18n = {
        dayNames: [
            "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
            "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
        ],
        monthNames: [
            "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
            "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"
        ]
    };

    // For convenience...
    Date.prototype.format = function (mask, utc) {
        return dateFormat(this, mask, utc);
    };

What is the `dateFormat()` function? – nnnnnn Dec 19 '13 at 12:54 — nnnnnn, Dec 19 '13 at 12:54
@nnnnnn i add one plugin for dateFormat(). – Nimesh Vaghasiya Dec 20 '13 at 04:41 — Nimesh Vaghasiya, Dec 20 '13 at 04:41

Compare dates with javascript

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