Compare two dates with JavaScript

Question

Can someone suggest a way to compare the values of two dates greater than, less than, and not in the past using JavaScript? The values will be coming from text boxes.

Dimitri

When it comes to DateTime and manipulation in JS, I look no further than momentjs :) – Marionmarionette

no need to use momentjs to compare 2 dates. Just use pure javascript's Date object. Check main answer for more details. – Shull

You can refer following answer : #4812652 Check getDateDifference and getDifferenceInDays if it can help. – Homeland

I'll give you a reason to look further than Moment.js (which I love, BUT...): Don't use for looping loads – Stelmach

For a useful function to get the time difference separated into units (seconds, minutes, hours, etc.), see the answer at #1968667. That answer is now also available at https://mcmap.net/q/36525/-how-to-calculate-number-of-days-between-two-dates. – Combo

For those like me who may have come along later, moment.js is now in "maintenance mode," i.e. no longer being actively developed. – Watering

For those that have come along even later, moment.js is not only in maintenance mode, but it's a huge library (4.21mb!). If you only need simple functionality like comparing two dates, then you might try a tiny (20kb) lib I've been working on npmjs.com/package/easy-dates – Kalamazoo

Answer 1

The Date object will do what you want - construct one for each date, then compare them using the >, <, <= or >=.

The ==, !=, ===, and !== operators require you to use date.getTime() as in

var d1 = new Date();
var d2 = new Date(d1);
var same = d1.getTime() === d2.getTime();
var notSame = d1.getTime() !== d2.getTime();

to be clear just checking for equality directly with the date objects won't work

var d1 = new Date();
var d2 = new Date(d1);

console.log(d1 == d2);   // prints false (wrong!) 
console.log(d1 === d2);  // prints false (wrong!)
console.log(d1 != d2);   // prints true  (wrong!)
console.log(d1 !== d2);  // prints true  (wrong!)
console.log(d1.getTime() === d2.getTime()); // prints true (correct)

I suggest you use drop-downs or some similar constrained form of date entry rather than text boxes, though, lest you find yourself in input validation hell.

---

For the curious, date.getTime() documentation:

Returns the numeric value of the specified date as the number of milliseconds since January 1, 1970, 00:00:00 UTC. (Negative values are returned for prior times.)

Thadthaddaus

Even Ace's method is not failsafe. You need to reset the milliseconds first, and you might even want to reset the whole time. date1.setHours(0); date1.setMinutes(0); date1.setSeconds(0); date1.setMilliseconds(0); That combined with using .getTime() will give you an accurate compare result – Driblet

@patrick, suggest calling setHours(0,0,0,0) this way. Eliminates the need for calling setMinutes() etc. Also, executes faster. – Actually

avoiding == or === to get desired result: jsfiddle.net/P4y5J now >= anotherNow && now <= anotherNow IS true FYI – Eldest

You can also compare the numeric values of your dates in order to avoid comparing the objects themselves: date1.valueOf() == date2.valueOf() – Ludwig

@Actually even shorter than setHours(0,0,0,0) and getTime() would be d1.toDateString() === d2.toDateString() if you just wanted to compare the 'date part of the Date' only rather than the 'date and time parts of the Date' (how confusing can naming be ;-) – Jolo

Comment 1/2: @Driblet Even Ace's method is not failsafe. You need to reset the milliseconds first Why? The amount of votes suggests a lot of people agree, but I can't find anything in the mdn constructor docs or getTime that imply you need to do this. I may be misunderstanding some nuance though. – Enrol

Comment 2/2: @Driblet In my previous reply, I'm assuming moonshadow used to be named Ace because I can't find anyone here with that name. If they changed their name, perhaps they changed their answer, too, and your comment no longer applies? – Enrol

@DanielKaplan the resetting of milliseconds is used when you want to compare the dates but ignore the time. Meaning if the date is the same but they have different times and you check for equality you will get true as the result. – Onyx

Patrick's advice only applies if you want to compare dates and ignore their time component. That isn't always the case. Also you may need that information if you want to consider time zones in your comparison. There's more to say about time zones, but it's worthy of its own post. /cc @Onyx Thanks for enlightening me! – Enrol

Answer 2

Compare < and > just as usual, but anything involving == or === should use a + prefix. Like so:

const x = new Date('2013-05-23');
const y = new Date('2013-05-23');

// less than, greater than is fine:
console.log('x < y', x < y); // false
console.log('x > y', x > y); // false
console.log('x <= y', x <= y); // true
console.log('x >= y', x >= y); // true
console.log('x === y', x === y); // false, oops!

// anything involving '==' or '===' should use the '+' prefix
// it will then compare the dates' millisecond values

console.log('+x === +y', +x === +y); // true

Pome

terribly slow :) I prefer x.getTime() === y.getTime() method, both readable and extremely fast see jsperf – Pose

The + operator attempts to convert the expression into a Number. Date.valueOf() is used for the conversion (which returns the same thing as Date.getTime(). – Movement

@daniel < and <= use same algorithm (abstract relational comparison), likewise for > and >=. The answer was popular but wrong. Please correct the first line which I forgot to edit. – Movement

@Pose The original jsperf URL is down, but it has been archived on web.archive.org. You can even run the benchmark from the archived version. TL;DR: comparing using .getTime() is at least 100 times quicker than comparing the Date objects directly. – Bierce

if standard == needs type coercion with +, does <= work correctly for the case the dates are equal? – Darrickdarrill

Answer 3

The easiest way to compare dates in javascript is to first convert it to a Date object and then compare these date-objects.

Below you find an object with three functions:

• dates.compare(a,b)

  Returns a number:

  • -1 if a < b
  • 0 if a = b
  • 1 if a > b
  • NaN if a or b is an illegal date

• dates.inRange (d,start,end)

  Returns a boolean or NaN:

  • true if d is between the start and end (inclusive)
  • false if d is before start or after end.
  • NaN if one or more of the dates are illegal.

• dates.convert

  Used by the other functions to convert their input to a date object. The input can be

  • a date-object : The input is returned as is.
  • an array: Interpreted as [year,month,day]. NOTE month is 0-11.
  • a number : Interpreted as number of milliseconds since 1 Jan 1970 (a timestamp)
  • a string : Several different formats is supported, like "YYYY/MM/DD", "MM/DD/YYYY", "Jan 31 2009" etc.
  • an object: Interpreted as an object with year, month and date attributes. NOTE month is 0-11.

.

// Source: http://stackoverflow.com/questions/497790
var dates = {
    convert:function(d) {
        // Converts the date in d to a date-object. The input can be:
        //   a date object: returned without modification
        //  an array      : Interpreted as [year,month,day]. NOTE: month is 0-11.
        //   a number     : Interpreted as number of milliseconds
        //                  since 1 Jan 1970 (a timestamp) 
        //   a string     : Any format supported by the javascript engine, like
        //                  "YYYY/MM/DD", "MM/DD/YYYY", "Jan 31 2009" etc.
        //  an object     : Interpreted as an object with year, month and date
        //                  attributes.  **NOTE** month is 0-11.
        return (
            d.constructor === Date ? d :
            d.constructor === Array ? new Date(d[0],d[1],d[2]) :
            d.constructor === Number ? new Date(d) :
            d.constructor === String ? new Date(d) :
            typeof d === "object" ? new Date(d.year,d.month,d.date) :
            NaN
        );
    },
    compare:function(a,b) {
        // Compare two dates (could be of any type supported by the convert
        // function above) and returns:
        //  -1 : if a < b
        //   0 : if a = b
        //   1 : if a > b
        // NaN : if a or b is an illegal date
        // NOTE: The code inside isFinite does an assignment (=).
        return (
            isFinite(a=this.convert(a).valueOf()) &&
            isFinite(b=this.convert(b).valueOf()) ?
            (a>b)-(a<b) :
            NaN
        );
    },
    inRange:function(d,start,end) {
        // Checks if date in d is between dates in start and end.
        // Returns a boolean or NaN:
        //    true  : if d is between start and end (inclusive)
        //    false : if d is before start or after end
        //    NaN   : if one or more of the dates is illegal.
        // NOTE: The code inside isFinite does an assignment (=).
       return (
            isFinite(d=this.convert(d).valueOf()) &&
            isFinite(start=this.convert(start).valueOf()) &&
            isFinite(end=this.convert(end).valueOf()) ?
            start <= d && d <= end :
            NaN
        );
    }
}

Starbuck

(a > b) - (a < b) is useful for sorting dates array – Pivot

Answer 4

The relational operators < <= > >= can be used to compare JavaScript dates:

var d1 = new Date(2013, 0, 1);
var d2 = new Date(2013, 0, 2);
d1 <  d2; // true
d1 <= d2; // true
d1 >  d2; // false
d1 >= d2; // false

However, the equality operators == != === !== cannot be used to compare the dates because:

1. If the operands have the same type, they are compared as follows:
   • Object: return true only if both operands reference the same object.

You can compare the value of dates for equality using any of these methods:

var d1 = new Date(2013, 0, 1);
var d2 = new Date(2013, 0, 1);
/*
 * note: d1 == d2 returns false as described above
 */
d1.getTime() == d2.getTime(); // true
d1.valueOf() == d2.valueOf(); // true
Number(d1)   == Number(d2);   // true
+d1          == +d2;          // true

Both Date.getTime() and Date.valueOf() return the number of milliseconds since January 1, 1970, 00:00 UTC. Both Number function and unary + operator call the valueOf() methods behind the scenes.

Movement

Answer 5

By far the easiest method is to subtract one date from the other and compare the result.

var oDateOne = new Date();
var oDateTwo = new Date();

console.log(oDateOne - oDateTwo === 0);
console.log(oDateOne - oDateTwo < 0);
console.log(oDateOne - oDateTwo > 0);

Emmalineemmalyn

Answer 6

Comparing dates in JavaScript is quite easy... JavaScript has built-in comparison system for dates which makes it so easy to do the comparison...

Just follow these steps for comparing 2 dates value, for example you have 2 inputs which each has a Date value in String and you to compare them...

1. you have 2 string values you get from an input and you'd like to compare them, they are as below:

var date1 = '01/12/2018';
var date2 = '12/12/2018';

2. They need to be Date Object to be compared as date values, so simply convert them to date, using new Date(), I just re-assign them for simplicity of explanation, but you can do it anyway you like:

date1 = new Date(date1);
date2 = new Date(date2);

3. Now simply compare them, using the > < >= <=

date1 > date2;  //false
date1 < date2;  //true
date1 >= date2; //false
date1 <= date2; //true

Toogood

Answer 7

Compare day only (ignoring time component):

Date.prototype.sameDay = function(d) {
  return this.getFullYear() === d.getFullYear()
    && this.getDate() === d.getDate()
    && this.getMonth() === d.getMonth();
}

Usage:

if(date1.sameDay(date2)) {
    // highlight day on calendar or something else clever
}

---

I no longer recommend modifying the prototype of built-in objects. Try this instead:

function isSameDay(d1, d2) {
  return d1.getFullYear() === d2.getFullYear() &&
    d1.getDate() === d2.getDate() &&
    d1.getMonth() === d2.getMonth();
}


console.log(isSameDay(new Date('Jan 15 2021 02:39:53 GMT-0800'), new Date('Jan 15 2021 23:39:53 GMT-0800')));
console.log(isSameDay(new Date('Jan 15 2021 10:39:53 GMT-0800'), new Date('Jan 16 2021 10:39:53 GMT-0800')));

N.B. the year/month/day will be returned for your timezone; I recommend using a timezone-aware library if you want to check if two dates are on the same day in a different timezone.

e.g.

> (new Date('Jan 15 2021 01:39:53 Z')).getDate()  // Jan 15 in UTC
14  // Returns "14" because I'm in GMT-08

Puffy

Answer 8

what format?

If you construct a Javascript Date object, you can just subtract them to get a milliseconds difference (edit: or just compare them) :

js>t1 = new Date()
Thu Jan 29 2009 14:19:28 GMT-0500 (Eastern Standard Time)
js>t2 = new Date()
Thu Jan 29 2009 14:19:31 GMT-0500 (Eastern Standard Time)
js>t2-t1
2672
js>t3 = new Date('2009 Jan 1')
Thu Jan 01 2009 00:00:00 GMT-0500 (Eastern Standard Time)
js>t1-t3
2470768442
js>t1>t3
true

Histrionics

Answer 9

Note - Compare Only Date Part:

When we compare two date in javascript. It takes hours, minutes and seconds also into consideration.. So If we only need to compare date only, this is the approach:

var date1= new Date("01/01/2014").setHours(0,0,0,0);

var date2= new Date("01/01/2014").setHours(0,0,0,0);

Now: if date1.valueOf()> date2.valueOf() will work like a charm.

Voidance

This is the answer I came to look for! – Beak

Answer 10

The simple way is,

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

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

Mullinax

This will not work for for == nor === – Colangelo

Answer 11

You can use this code:

var firstValue = "2012-05-12".split('-');
var secondValue = "2014-07-12".split('-');

 var firstDate=new Date();
 firstDate.setFullYear(firstValue[0],(firstValue[1] - 1 ),firstValue[2]);

 var secondDate=new Date();
 secondDate.setFullYear(secondValue[0],(secondValue[1] - 1 ),secondValue[2]);     

  if (firstDate > secondDate)
  {
   alert("First Date  is greater than Second Date");
  }
 else
  {
    alert("Second Date  is greater than First Date");
  }

And also check the MDN article for the Date class.

Dragoon

This assumes a specific year month date ordering of the string and would be a very fragile implementation for dates expressed in various locale formats. – Colangelo

Answer 12

SHORT ANSWER

Here is a function that return {boolean} if the from dateTime > to dateTime Demo in action

var from = '08/19/2013 00:00'
var to = '08/12/2013 00:00 '

function isFromBiggerThanTo(dtmfrom, dtmto){
   return new Date(dtmfrom).getTime() >=  new Date(dtmto).getTime() ;
}
console.log(isFromBiggerThanTo(from, to)); //true

Explanation

jsFiddle

var date_one = '2013-07-29 01:50:00',
date_two = '2013-07-29 02:50:00';
//getTime() returns the number of milliseconds since 01.01.1970.
var timeStamp_date_one = new Date(date_one).getTime() ; //1375077000000 
console.log(typeof timeStamp_date_one);//number 
var timeStamp_date_two = new Date(date_two).getTime() ;//1375080600000 
console.log(typeof timeStamp_date_two);//number 

since you are now having both datetime in number type you can compare them with any Comparison operations

( >, < ,= ,!= ,== ,!== ,>= AND <=)

Then

if you are familiar with C# Custom Date and Time Format String this library should do the exact same thing and help you format your date and time dtmFRM whether you are passing in date time string or unix format

Usage

var myDateTime = new dtmFRM();

alert(myDateTime.ToString(1375077000000, "MM/dd/yyyy hh:mm:ss ampm"));
//07/29/2013 01:50:00 AM

alert(myDateTime.ToString(1375077000000,"the year is yyyy and the day is dddd"));
//this year is 2013 and the day is Monday

alert(myDateTime.ToString('1/21/2014', "this month is MMMM and the day is dd"));
//this month is january and the day is 21

DEMO

all you have to do is passing any of these format pacified in the library js file

Principate

Answer 13

var date = new Date(); // will give you todays date.

// following calls, will let you set new dates.
setDate()   
setFullYear()   
setHours()  
setMilliseconds()   
setMinutes()    
setMonth()  
setSeconds()    
setTime()

var yesterday = new Date();
yesterday.setDate(...date info here);

if(date>yesterday)  // will compare dates

Barrack

Answer 14

function datesEqual(a, b)
{
   return (!(a>b || b>a))
}

Saberhagen

Answer 15

Via Moment.js

Jsfiddle: http://jsfiddle.net/guhokemk/1/

function compare(dateTimeA, dateTimeB) {
    var momentA = moment(dateTimeA,"DD/MM/YYYY");
    var momentB = moment(dateTimeB,"DD/MM/YYYY");
    if (momentA > momentB) return 1;
    else if (momentA < momentB) return -1;
    else return 0;
}

alert(compare("11/07/2015", "10/07/2015"));

The method returns 1 if dateTimeA is greater than dateTimeB

The method returns 0 if dateTimeA equals dateTimeB

The method returns -1 if dateTimeA is less than dateTimeB

Arcane

Answer 16

BEWARE THE TIMEZONE

A javascript date has no notion of timezone. It's a moment in time (ticks since the epoch) with handy functions for translating to and from strings in the "local" timezone. If you want to work with dates using date objects, as everyone here is doing, you want your dates to represent UTC midnight at the start of the date in question. This is a common and necessary convention that lets you work with dates regardless of the season or timezone of their creation. So you need to be very vigilant to manage the notion of timezone, particularly when you create your midnight UTC Date object.

Most of the time, you will want your date to reflect the timezone of the user. Click if today is your birthday. Users in NZ and US click at the same time and get different dates. In that case, do this...

// create a date (utc midnight) reflecting the value of myDate and the environment's timezone offset.
new Date(Date.UTC(myDate.getFullYear(),myDate.getMonth(), myDate.getDate()));

Sometimes, international comparability trumps local accuracy. In that case, do this...

// the date in London of a moment in time. Device timezone is ignored.
new Date(Date.UTC(myDate.getUTCYear(), myDate.getyUTCMonth(), myDate.getUTCDate()));

Now you can directly compare your date objects as the other answers suggest.

Having taken care to manage timezone when you create, you also need to be sure to keep timezone out when you convert back to a string representation. So you can safely use...

• toISOString()
• getUTCxxx()
• getTime() //returns a number with no time or timezone.
• .toLocaleDateString("fr",{timezone:"UTC"}) // whatever locale you want, but ALWAYS UTC.

And totally avoid everything else, especially...

• getYear(),getMonth(),getDate()

Avion

Answer 17

Just to add yet another possibility to the many existing options, you could try:

if (date1.valueOf()==date2.valueOf()) .....

...which seems to work for me. Of course you do have to ensure that both dates are not undefined...

if ((date1?date1.valueOf():0)==(date2?date2.valueOf():0) .....

This way we can ensure that a positive comparison is made if both are undefined also, or...

if ((date1?date1.valueOf():0)==(date2?date2.valueOf():-1) .....

...if you prefer them not to be equal.

Chud

Answer 18

If following is your date format, you can use this code:

var first = '2012-11-21';
var second = '2012-11-03';
if(parseInt(first.replace(/-/g,""),10) > parseInt(second.replace(/-/g,""),10)){
   //...
}

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

Sihun

If it already is in ISO8601 format (YYYY-MM-DD) you don't need to remove any characters or convert it to an integer. Just compare the strings first == second or first < second or first > second. That's one of the many beauties with ISO8601 compared to MM/DD/YY, DD/MM/YY, YY/DD/MM, DD/YY/MM or MM/YY/DD. – Starbuck

Answer 19

Say you got the date objects A and B, get their EPOC time value, then subtract to get the difference in milliseconds.

var diff = +A - +B;

That's all.

Salinasalinas

Answer 20

Subtract two date get the difference in millisecond, if you get 0 it's the same date

function areSameDate(d1, d2){
    return d1 - d2 === 0
}

Superinduce

Answer 21

One way to compare two dates is to use the dates.js library.

The Date.compare(Date date1, Date date2) method that returns a number which means the one of following result:

• -1 = date1 is less than date2.
• 0 = values are equal.
• 1 = date1 is greater than date2.

Herald

Answer 22

In order to create dates from free text in JavaScript you need to parse it into the Date object.

You could use Date.parse() which takes free text and tries to convert it into a new date but if you have control over the page I would recommend using HTML select boxes instead or a date picker such as the YUI calendar control or the jQuery UI Datepicker.

Once you have a date, as other people have pointed out, you can use simple arithmetic to subtract the dates and convert it back into a number of days by dividing the number (in seconds) by the number of seconds in a day (60*60*24 = 86400).

Refulgent

Answer 23

Performance

Today 2020.02.27 I perform tests of chosen solutions on Chrome v80.0, Safari v13.0.5 and Firefox 73.0.1 on MacOs High Sierra v10.13.6

Conclusions

• solutions d1==d2 (D) and d1===d2 (E) are fastest for all browsers
• solution getTime (A) is faster than valueOf (B) (both are medium fast)
• solutions F,L,N are slowest for all browsers

Details

In below snippet solutions used in performance tests are presented. You can perform test in you machine HERE

function A(d1,d2) {
	return d1.getTime() == d2.getTime();
}

function B(d1,d2) {
	return d1.valueOf() == d2.valueOf();
}

function C(d1,d2) {
	return Number(d1)   == Number(d2);
}

function D(d1,d2) {
	return d1 == d2;
}

function E(d1,d2) {
	return d1 === d2;
}

function F(d1,d2) {
	return (!(d1>d2 || d2>d1));
}

function G(d1,d2) {
	return d1*1 == d2*1;
}

function H(d1,d2) {
	return +d1 == +d2;
}

function I(d1,d2) {
	return !(+d1 - +d2);
}

function J(d1,d2) {
	return !(d1 - d2);
}

function K(d1,d2) {
	return d1 - d2 == 0;
}

function L(d1,d2) {
	return !((d1>d2)-(d1<d2));
}

function M(d1,d2) {
  return d1.getFullYear() === d2.getFullYear()
    && d1.getDate() === d2.getDate()
    && d1.getMonth() === d2.getMonth();
}

function N(d1,d2) {
	return (isFinite(d1.valueOf()) && isFinite(d2.valueOf()) ? !((d1>d2)-(d1<d2)) : false );
}


// TEST

let past= new Date('2002-12-24'); // past
let now= new Date('2020-02-26');  // now

console.log('Code  d1>d2  d1<d2  d1=d2')
var log = (l,f) => console.log(`${l}     ${f(now,past)}  ${f(past,now)}  ${f(now,now)}`);

log('A',A);
log('B',B);
log('C',C);
log('D',D);
log('E',E);
log('G',G);
log('H',H);
log('I',I);
log('J',J);
log('K',K);
log('L',L);
log('M',M);
log('N',N);

p {color: red}

<p>This snippet only presents tested solutions (it not perform tests itself)</p>

Results for chrome

Ragtime

But d1==d2 or d1===d2 is useless in the context of the question. – Sanfordsanfourd

Answer 24

var date_today=new Date();
var formated_date = formatDate(date_today);//Calling formatDate Function

var input_date="2015/04/22 11:12 AM";

var currentDateTime = new Date(Date.parse(formated_date));
var inputDateTime   = new Date(Date.parse(input_date));

if (inputDateTime <= currentDateTime){
    //Do something...
}

function formatDate(date) {
    var hours = date.getHours();
    var minutes = date.getMinutes();
    var ampm = hours >= 12 ? 'PM' : 'AM';

    hours = hours % 12;
    hours = hours ? hours : 12; // the hour '0' should be '12'
    hours   = hours < 10 ? '0'+hours : hours ;

    minutes = minutes < 10 ? '0'+minutes : minutes;

    var strTime = hours+":"+minutes+ ' ' + ampm;
    return  date.getFullYear()+ "/" + ((date.getMonth()+1) < 10 ? "0"+(date.getMonth()+1) :
    (date.getMonth()+1) ) + "/" + (date.getDate() < 10 ? "0"+date.getDate() :
    date.getDate()) + " " + strTime;
}

Nogging

Answer 25

An Improved version of the code posted by "some"

/* Compare the current date against another date.
 *
 * @param b  {Date} the other date
 * @returns   -1 : if this < b
 *             0 : if this === b
 *             1 : if this > b
 *            NaN : if a or b is an illegal date
*/ 
Date.prototype.compare = function(b) {
  if (b.constructor !== Date) {
    throw "invalid_date";
  }

 return (isFinite(this.valueOf()) && isFinite(b.valueOf()) ? 
          (this>b)-(this<b) : NaN 
        );
};

usage:

  var a = new Date(2011, 1-1, 1);
  var b = new Date(2011, 1-1, 1);
  var c = new Date(2011, 1-1, 31);
  var d = new Date(2011, 1-1, 31);

  assertEquals( 0, a.compare(b));
  assertEquals( 0, b.compare(a));
  assertEquals(-1, a.compare(c));
  assertEquals( 1, c.compare(a));

Middlesworth

Presumably a is the Date instance on which the method is called. In which case can a be an invalid date, but still be a Date instance? – Chef

Answer 26

I usually store Dates as timestamps(Number) in databases.

When I need to compare, I simply compare among those timestamps or

convert it to Date Object and then compare with > <if necessary.

Note that == or === does not work properly unless your variables are references of the same Date Object.

Convert those Date objects to timestamp(number) first and then compare equality of them.

---

Date to Timestamp

var timestamp_1970 = new Date(0).getTime(); // 1970-01-01 00:00:00
var timestamp = new Date().getTime(); // Current Timestamp

Timestamp to Date

var timestamp = 0; // 1970-01-01 00:00:00
var DateObject = new Date(timestamp);

Oversold

This is the best answer - and the fastest jsperf.com/comparing-date-objects – Comeau

Answer 27

Before comparing the Dates object, try setting both of their milliseconds to zero like Date.setMilliseconds(0);.

In some cases where the Date object is dynamically created in javascript, if you keep printing the Date.getTime(), you'll see the milliseconds changing, which will prevent the equality of both dates.

Grecian

Answer 28

Let's suppose that you deal with this 2014[:-/.]06[:-/.]06 or this 06[:-/.]06[:-/.]2014 date format, then you may compare dates this way

var a = '2014.06/07', b = '2014-06.07', c = '07-06/2014', d = '07/06.2014';

parseInt(a.replace(/[:\s\/\.-]/g, '')) == parseInt(b.replace(/[:\s\/\.-]/g, '')); // true
parseInt(c.replace(/[:\s\/\.-]/g, '')) == parseInt(d.replace(/[:\s\/\.-]/g, '')); // true
parseInt(a.replace(/[:\s\/\.-]/g, '')) < parseInt(b.replace(/[:\s\/\.-]/g, '')); // false
parseInt(c.replace(/[:\s\/\.-]/g, '')) > parseInt(d.replace(/[:\s\/\.-]/g, '')); // false

As you can see, we strip separator(s) and then compare integers.

Italy

Answer 29

My simple answer for this question

checkDisabled(date) {
    const today = new Date()
    const newDate = new Date(date._d)
    if (today.getTime() > newDate.getTime()) {
        return true
    }
    return false
}
       

Sledge

Answer 30

If both of your dates come in the format "YYYY-MM-DD", you can skip the Date object and compare strings directly.

This works because of how the strings are compared in JS

let date1 = '2022-12-13';
let date2 = '2022-02-13';

console.log(`${date1} > ${date2}`, date1 > date2);
console.log(`${date1} < ${date2}`, date1 < date2);
console.log(`${date1} == ${date2}`, date1 == date2);

Shearwater

Answer 31

        from_date ='10-07-2012';
        to_date = '05-05-2012';
        var fromdate = from_date.split('-');
        from_date = new Date();
        from_date.setFullYear(fromdate[2],fromdate[1]-1,fromdate[0]);
        var todate = to_date.split('-');
        to_date = new Date();
        to_date.setFullYear(todate[2],todate[1]-1,todate[0]);
        if (from_date > to_date ) 
        {
            alert("Invalid Date Range!\nStart Date cannot be after End Date!")

            return false;
        }

Use this code to compare the date using javascript.

Thanks D.Jeeva

Confessional

I think this is a good answer because we have "dd/mm/yy" format and we have to do it to compare both dates. I don't know if it is the best answer but it is enough. Thank you for share. – Cystitis

Answer 32

var curDate=new Date();
var startDate=document.forms[0].m_strStartDate;

var endDate=document.forms[0].m_strEndDate;
var startDateVal=startDate.value.split('-');
var endDateVal=endDate.value.split('-');
var firstDate=new Date();
firstDate.setFullYear(startDateVal[2], (startDateVal[1] - 1), startDateVal[0]);

var secondDate=new Date();
secondDate.setFullYear(endDateVal[2], (endDateVal[1] - 1), endDateVal[0]);
if(firstDate > curDate) {
    alert("Start date cannot be greater than current date!");
    return false;
}
if (firstDate > secondDate) {
    alert("Start date cannot be greater!");
    return false;
}

Domesticity

Answer 33

Here is what I did in one of my projects,

function CompareDate(tform){
     var startDate = new Date(document.getElementById("START_DATE").value.substring(0,10));
     var endDate = new Date(document.getElementById("END_DATE").value.substring(0,10));

     if(tform.START_DATE.value!=""){
         var estStartDate = tform.START_DATE.value;
         //format for Oracle
         tform.START_DATE.value = estStartDate + " 00:00:00";
     }

     if(tform.END_DATE.value!=""){
         var estEndDate = tform.END_DATE.value;
         //format for Oracle
         tform.END_DATE.value = estEndDate + " 00:00:00";
     }

     if(endDate <= startDate){
         alert("End date cannot be smaller than or equal to Start date, please review you selection.");
         tform.START_DATE.value = document.getElementById("START_DATE").value.substring(0,10);
         tform.END_DATE.value = document.getElementById("END_DATE").value.substring(0,10);
         return false;
     }
}

calling this on form onsubmit. hope this helps.

Covenantor

Answer 34

Hi Here is my code to compare dates . In my case i am doing a check to not allow to select past dates.

var myPickupDate = <pick up date> ;
var isPastPickupDateSelected = false;
var currentDate = new Date();

if(currentDate.getFullYear() <= myPickupDate.getFullYear()){
    if(currentDate.getMonth()+1 <= myPickupDate.getMonth()+1 || currentDate.getFullYear() < myPickupDate.getFullYear()){
                        if(currentDate.getDate() <= myPickupDate.getDate() || currentDate.getMonth()+1 < myPickupDate.getMonth()+1 || currentDate.getFullYear() < myPickupDate.getFullYear()){
                                            isPastPickupDateSelected = false;
                                            return;
                                        }
                    }
}
console.log("cannot select past pickup date");
isPastPickupDateSelected = true;

Takeoff

Answer 35

Another way to compare two dates, is through the toISOString() method. This is especially useful when comparing to a fixed date kept in a string, since you can avoid creating a short-lived object. By virtue of the ISO 8601 format, you can compare these strings lexicographically (at least when you're using the same timezone).

I'm not necessarily saying that it's better than using time objects or timestamps; just offering this as another option. There might be edge cases when this could fail, but I haven't stumbled upon them yet :)

Antiserum

Answer 36

All the above-given answers only solved one thing: compare two dates.

Indeed, they seem to be the answers to the question, but a big part is missing:

What if I want to check whether a person is fully 18 years old?

Unfortunately, NONE of the above-given answers would be able to answer that question.

For example, the current time (around the time when I started to type these words) is Fri Jan 31 2020 10:41:04 GMT-0600 (Central Standard Time), while a customer enters his Date of Birth as "01/31/2002".

If we use "365 days/year", which is "31536000000" milliseconds, we would get the following result:

       let currentTime = new Date();
       let customerTime = new Date(2002, 1, 31);
       let age = (currentTime.getTime() - customerTime.getTime()) / 31536000000
       console.log("age: ", age);

with the following print-out:

       age: 17.92724710838407

But LEGALLY, that customer is already 18 years old. Even he enters "01/30/2002", the result would still be

       age: 17.930039743467784

which is less than 18. The system would report the "under age" error.

And this would just keep going for "01/29/2002", "01/28/2002", "01/27/2002" ... "01/05/2002", UNTIL "01/04/2002".

A system like that would just kill all the customers who were born between 18 years 0 days and 18 years 26 days ago, because they are legally 18 years old, while the system shows "under age".

The following is an answer to a question like that:

invalidBirthDate: 'Invalid date. YEAR cannot be before 1900.',
invalidAge: 'Invalid age. AGE cannot be less than 18.',

public static birthDateValidator(control: any): any {
    const val = control.value;
    if (val != null) {
        const slashSplit = val.split('-');
        if (slashSplit.length === 3) {
            const customerYear = parseInt(slashSplit[0], 10);
            const customerMonth = parseInt(slashSplit[1], 10);
            const customerDate = parseInt(slashSplit[2], 10);
            if (customerYear < 1900) {
                return { invalidBirthDate: true };
            } else {
                const currentTime = new Date();
                const currentYear = currentTime.getFullYear();
                const currentMonth = currentTime.getMonth() + 1;
                const currentDate = currentTime.getDate();
                if (currentYear - customerYear < 18) {
                    return { invalidAge: true };
                } else if (
                    currentYear - customerYear === 18 &&
                    currentMonth - customerMonth < 0) {
                    return { invalidAge: true };
                } else if (
                    currentYear - customerYear === 18 &&
                    currentMonth - customerMonth === 0 &&
                    currentDate - customerDate < 0) {
                    return { invalidAge: true };
                } else {
                    return null;
                }
            }
        }
    }
}

Animism

If you post a new question asking "how to check in JS if date is at least X years ago", this would make a good answer. I suspect it can be simplified by calculating what birthday+X entire years is (you can add years to JS dates), and then comparing with >= with a new Date() – Holiness

Sure. Of course there might be better answers. My answer was just to show the POINT. It might not be the best answer. It'd be great if you could simplify it!😁👍 – Animism

Answer 37

Solution

To get the difference in days of two dates, allowing to ignore time:

const MS_PER_DAY = 24 * 60 * 60 * 1000;

const compareDates = (a/*: Date*/, b/*: Date*/, ignoreTime = true)/*: number*/ => {
  if (ignoreTime) {
    a.setHours(0, 0, 0, 0);
    b.setHours(0, 0, 0, 0);
  }
  const diffInMs = a.getTime() - b.getTime();
  return Math.round(diffInMs / MS_PER_DAY);
};

Bullate

Answer 38

You can date compare as most simple and understandable way like.

<input type="date" id="getdate1" />
<input type="date" id="getdate2" />

let suppose you have two date input you want to compare them.

so firstly write a common method to parse date.

 <script type="text/javascript">
            function parseDate(input) {
             var datecomp= input.split('.'); //if date format 21.09.2017

              var tparts=timecomp.split(':');//if time also giving
              return new Date(dparts[2], dparts[1]-1, dparts[0], tparts[0], tparts[1]);
// here new date(  year, month, date,)
            }
        </script>

parseDate() is the make common method for parsing the date. now you can checks your date =, > ,< any type of compare

    <script type="text/javascript">

              $(document).ready(function(){
              //parseDate(pass in this method date);
                    Var Date1=parseDate($("#getdate1").val());
                        Var Date2=parseDate($("#getdate2").val());
               //use any oe < or > or = as per ur requirment 
               if(Date1 = Date2){
         return false;  //or your code {}
}
 });
    </script>

For Sure this code will help you.

Mccullough

Answer 39

function compare_date(date1, date2){
const x = new Date(date1)
const y = new Date(date2)
function checkyear(x, y){
    if(x.getFullYear()>y.getFullYear()){
        return "Date1 > Date2"
    }
    else if(x.getFullYear()<y.getFullYear()){
        return "Date2 > Date1"
    }
    else{
        return checkmonth(x, y)
    }
}
function checkmonth(x, y){
    if(x.getMonth()>y.getFullYear()){
        return "Date1 > Date2"
    }
    else if(x.getMonth()<y.getMonth){
        return "Date2 > Date1"
    }
    else {
        return checkDate(x, y)
    }
}
function checkDate(x, y){
    if(x.getDate()>y.getFullYear()){
        return "Date1 > Date2"
    }
    else if(x.getDate()<y.getDate()){
        return "Date2 > Date1"
    }
    else {
        return checkhour(x,y)
    }
}
function checkhour(x, y){
    if(x.getHours()>y.getHours()){
        return "Date1 > Date2"
    }
    else if(x.getHours()<y.getHours()){
        return "Date2 > Date1"
    }
    else {
        return checkhmin(x,y)
    }
}
function checkhmin(x,y){
    if(x.getMinutes()>y.getMinutes()){
        return "Date1 > Date2"
    }
    else if(x.getMinutes()<y.getMinutes()){
        return "Date2 > Date1"
    }
    else {
        return "Date1 = Date2"
    }
}
return checkyear(x, y)

Helmuth

Answer 40

sort way on JS

const date1 = '2022-01-01T00:00:00.000Z';
const date2 = '2022-02-01T00:00:00.000Z';

const diffDays = Math.ceil(Math.abs(new Date(date2).getTime() - new Date(date1).getTime()) / 86400000);
console.log(diffDays);

Greylag

Answer 41

            var months = ["jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec"];
        
        var selectedDate= $('#hstdtContractTodate').val() ; //23-Feb-2023
            
        var date1=new Date((selectedDate.split("-")[2])
                    +"/"+(months.indexOf(selectedDate.split("-")[1].toLowerCase()) + 1)
                    +"/"+(selectedDate.split("-")[0])); //  year/month/day
        
        var currentDate = new Date().toDateString();


        var currdate = new Date((currentDate.split(" ")[3]) 
                            + "/" + (months.indexOf(currentDate.split(" ")[1].toLowerCase()) + 1) 
                            + "/" + (currentDate.split(" ")[2]));  //  year/month/day
        
        alert(currdate.getTime()===date1.getTime())

Fretted

Answer 42

We know that subtracting two dates gives you the difference between two dates in milliseconds:

function compareTwoDates(d1, d2){
    const date1 = new Date(d1);
    const date2 = new Date(d2);
    return date1 - date2; 
}

Check the returned number from function if:

• -1: date1 is less than date2.
• 0 : two dates are equal.
• 1 : date1 is greater than date2.

Example of use:

function compareTwoDates(d1, d2) {
  const date1 = new Date(d1);
  const date2 = new Date(d2);
  return date1 - date2;
}
let dateString1 = '2023-06-22';
let dateString2 = '2023-06-23';
let datesComparisonResult = compareTwoDates(dateString1, dateString2);
if (datesComparisonResult > 0) { //1
  console.log(`${dateString1} is greater than ${dateString2}`)
} else if (datesComparisonResult < 0) { //-1
  console.log(`${dateString1} is less than ${dateString2}`)
} else { //0
  console.log(`Both dates are equal`)
}

Announce

Answer 43

In this code time is not considered.

let date = "put date here";

let dateNow =new Date(Date.now()).toLocaleDateString();
dateNow = new Date(dateNow);

let dateVerified = new Date(date).toLocaleDateString();
dateVerified =new Date(dateVerified);

console.log(dateNow);
console.log(dateVerified );

console.log(dateNow-dateVerified );  //if 0 -> same date or 'today'

Heckman

Answer 44

try this while compare date should be iso format "yyyy-MM-dd" if you want to compare only dates use this datehelper

<a href="https://plnkr.co/edit/9N8ZcC?p=preview"> Live Demo</a>

Pernick

Answer 45

If you are using **REACT OR REACT NATIVE**, use this and it will work (Working like charm)

If the two dates are the same, it will return TRUE otherwise FALSE

const compareDate = (dateVal1, dateVal2) => {
        if (dateVal1.valueOf() === dateVal2.valueOf()){
            return true;
        }
        else { return false;}
    }

Spokeshave

you answer looks like @Sanjeev Singh answer, can you explain what is the differnace ? – Coopersmith

I didn't do copy and paste. Remember I said the code works for React and React Native App. I just created a functional component that will compare the two dates and return either true or false value. – Spokeshave

Infact there is a big difference between@Sanjeev code and mine. Others are writting solutions for javascript, while I choosed to write for React.js and React Native. – Spokeshave

Answer 46

Try using this code

var f =date1.split("/");

var t =date2.split("/");

var x =parseInt(f[2]+f[1]+f[0]);

var y =parseInt(t[2]+t[1]+t[0]);

if(x > y){
    alert("date1 is after date2");
}

else if(x < y){
    alert("date1 is before date2");
}

else{
    alert("both date are same");
}

Beater

There's absolutely no reason to do string splitting on a date like that when you can just use the getMinutes, getSeconds, etc methods. – Cardialgia

Why the hell do I keep losing reputation when this answer gets downvoted? – Cardialgia

Answer 47

using momentjs for dates manipulation.

For checking one date is same or after as another by using

isSameOrAfter() method

moment('2010-10-20').isSameOrAfter('2010-10-20') //true;

For checking one date is after as another by using isAfter() method

moment('2020-01-20').isAfter('2020-01-21'); // false
moment('2020-01-20').isAfter('2020-01-19'); // true

For checking one date is before another by using isBefore() method.

moment('2020-01-20').isBefore('2020-01-21'); // true
moment('2020-01-20').isBefore('2020-01-19'); // false

For checking one date is same as another by using isSame() method

moment('2020-01-20').isSame('2020-01-21'); // false
moment('2020-01-20').isSame('2020-01-20'); // true

Michelinemichell

Shouldn't need additional JavaScript mods to accomplish this. – Sorel

Answer 48

Dates comparison:

var str1  = document.getElementById("Fromdate").value;
var str2  = document.getElementById("Todate").value;
var dt1   = parseInt(str1.substring(0,2),10); 
var mon1  = parseInt(str1.substring(3,5),10);
var yr1   = parseInt(str1.substring(6,10),10); 
var dt2   = parseInt(str2.substring(0,2),10); 
var mon2  = parseInt(str2.substring(3,5),10); 
var yr2   = parseInt(str2.substring(6,10),10); 
var date1 = new Date(yr1, mon1, dt1); 
var date2 = new Date(yr2, mon2, dt2); 

if(date2 < date1)
{
   alert("To date cannot be greater than from date");
   return false; 
} 
else 
{ 
   alert("Submitting ...");
   document.form1.submit(); 
} 

Meredeth

There are so many things that don't fit the question and make (bad) assumptions: Reading a (localized) date representation from an HTML-element, splitting these string-representations into the separate components by using a very optimistic extraction method; creating new dates based on the data (which might be invalid); not using time; failing if date 2 is before date 1 - but succeeding if it is equal or greater - not mentioning how dates can actually be compared. – Wulf