regular expression to validate datetime format (MM/DD/YYYY)

Question

I am trying to validate datetime format MM/DD/YYYY. Here is the code I am trying please help.

 function ValidateDate(testdate) {
        var Status
        var reg = /^(((0[1-9]|[12]\d|3[01])\/(0[13578]|1[02])\/((19|[2-9]\d)\d{2}))|((0[1-9]|[12]\d|30)\/(0[13456789]|1[012])\/((19|[2-9]\d)\d{2}))|((0[1-9]|1\d|2[0-8])\/02\/((19|[2-9]\d)\d{2}))|(29\/02\/((1[6-9]|[2-9]\d)(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00))))$/g;
        if (!reg.test(testdate)) {
            Status = false;
        }
        return Status;
    }

Refer to http://www.devnetwork.net/viewtopic.php?f=29&t=13795 — Deadlock, Mar 04 '13 at 07:24
Trying to validate a date with a regular expression is a good way to go quickly insane - getting it structured to accept all the days of each month, but not invalid days of each month causes a combinatorial explosion. Think about it this way ... you want to reject the 32nd of any month, the 31st for several months, including 06/31 of any year, you have to accept 02/28 every year but reject 02/29 most years, though you should accept it if the year is divisible by 4 but not if by 100, though if the year is divisible by 400 then 02/29 is ok. — Bevan, Mar 04 '13 at 08:18

score 91 · Accepted Answer · edited Sep 12 '22 at 19:44

91

Try your regex with a tool like http://jsregex.com/ (There is many) or better, a unit test.

For a native validation:

function validateDate(testdate) {
    var date_regex = /^\d{2}\/\d{2}\/\d{4}$/ ;
    return date_regex.test(testdate);
}

In your case, to validate (MM/DD/YYYY), with a year between 1900 and 2099, I'll write it like that:

function validateDate(testdate) {
    var date_regex = /^(0[1-9]|1[0-2])\/(0[1-9]|1\d|2\d|3[01])\/(19|20)\d{2}$/ ;
    return date_regex.test(testdate);
}

edited Sep 12 '22 at 19:44

Scott Marcus

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answered Mar 04 '13 at 07:31

noirbizarre

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I edited to add a more complex validation. – noirbizarre Mar 04 '13 at 07:43
@Supreet: This is only weak validation. You still need a thorough validation on the server side. – nhahtdh Mar 04 '13 at 07:57
@nhahtdh : how can i make a server side check to validate the format? – Supreet Mar 04 '13 at 08:03
@Supreet: If you are using PHP: http://php.net/manual/en/function.checkdate.php – nhahtdh Mar 04 '13 at 08:32
@nhahtdh ; i am working in .net – Supreet Mar 04 '13 at 09:10
@Supreet: Not sure if they are relevant, but here you go: http://stackoverflow.com/questions/939802/date-validation-with-asp-net-validator and http://stackoverflow.com/a/371996/1400768 Those are many times better than using a regex to validate a date. – nhahtdh Mar 04 '13 at 09:13
This is a naïve validation just to ensure that the pattern match. You still have to validate it server side, I totally agree. – noirbizarre Mar 04 '13 at 09:48
1

it does not invalidate 02/30/2016 date. – Jitendra Pancholi Aug 30 '16 at 07:00
1

Your simple regex pattern was exactly what I was looking for. Thanks – BrianLegg Jan 25 '17 at 17:14
1

@noirbizarre This does not work for validateDate("02/31/1999"). It returns true. Ca you please correct it also? – Rahul Sep 03 '20 at 07:45

score 14 · Answer 2 · answered Sep 23 '15 at 14:26

The answer marked is perfect but for one scenario, where in the dd and mm are actually single digits. the following regex is perfect in this case:

    function validateDate(testdate) {
        var date_regex = /^(0?[1-9]|1[0-2])\/(0?[1-9]|1\d|2\d|3[01])\/(19|20)\d{2}$/ ;
        return date_regex.test(testdate);
    }

score 3 · Answer 3 · edited May 23 '17 at 10:31

based on this

dd-mm-yy

I modified the original to this:

^(?:(?:(?:0?[13578]|1[02]|(?:Jan|Mar|May|Jul|Aug|Oct|Dec))(\/|-|\.)31)\1|(?:(?:0?[1,3-9]|1[0-2]|(?:Jan|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec))(\/|-|\.)(?:29|30)\2))(?:(?:1[6-9]|[2-9]\d)?\d{2})$|^(?:(?:0?2|(?:Feb))(\/|-|\.)(?:29)\3(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00))))$|^(?:(?:0?[1-9]|(?:Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep))|(?:1[0-2]|(?:Oct|Nov|Dec)))(\/|-|\.)(?:0?[1-9]|1\d|2[0-8])\4(?:(?:1[6-9]|[2-9]\d)?\d{2})$

test the regex here

score 0 · Answer 4 · answered Mar 04 '13 at 07:25

0

var pattern = new RegExp((0|1)[0-9]\/[0-3][0-9]\/(19|20)[0-9]{2});
if(!testdate.match(pattern))
   return false;
else return true;

answered Mar 04 '13 at 07:25

MIIB

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Using `(0[0-9]|1[012])` is better for checking `MM`, in my opinion. – hjpotter92 Mar 04 '13 at 07:27
This will give syntax error. And even if you fix it, the regex is worse than what the OP has. – nhahtdh Mar 04 '13 at 07:27
@Dream Eater You're right – MIIB Mar 04 '13 at 07:28
This regex allows the date and month to be `00` which is invalid. – tftd Jun 04 '17 at 22:14

score 0 · Answer 5 · answered Jun 30 '14 at 11:25

you can look into this link and I hope this may be of great help as its was for me.

If you are using the regex given in the above link in Java code then use the following regex

"^(0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])[- /.](19|20)\\d\\d$"

As I noticed in your example you are using js function then this use regex

"^(0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])[- /.](19|20)\d\d$"

This will match a date in mm/dd/yyyy format from between 1900-01-01 and 2099-12-31, with a choice of four separators. and not to forget the

return regex.test(testdate);

score 0 · Answer 6 · edited Jan 01 '17 at 03:49

0

In this case, to validate Date (DD-MM-YYYY) or (DD/MM/YYYY), with a year between 1900 and 2099,like this with month and Days validation

if (!Regex.Match(txtDob.Text, @"^(0[1-9]|1[0-9]|2[0-9]|3[0,1])([/+-])(0[1-9]|1[0-2])([/+-])(19|20)[0-9]{2}$").Success)                  
{
   MessageBox.Show("InValid Date of Birth");
   txtDob.Focus();
}

edited Jan 01 '17 at 03:49

Divyang Desai

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answered Jan 01 '17 at 03:26

Nouman Ali

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score -3 · Answer 7 · answered Jul 06 '16 at 18:10

-3

It's long, but great:

new RegExp(/(?=\d)^(?:(?!(?:10\D(?:0?[5-9]|1[0-4])\D(?:1582))|(?:0?9\D(?:0?[3-9]|1[0-3])\D(?:1752)))((?:0?[13578]|1[02])|(?:0?[469]|11)(?!\/31)(?!-31)(?!\.31)|(?:0?2(?=.?(?:(?:29.(?!000[04]|(?:(?:1[^0-6]|[2468][^048]|[3579][^26])00))(?:(?:(?:\d\d)(?:[02468][048]|[13579][26])(?!\x20BC))|(?:00(?:42|3[0369]|2[147]|1[258]|09)\x20BC))))))|(?:0?2(?=.(?:(?:\d\D)|(?:[01]\d)|(?:2[0-8])))))([-.\/])(0?[1-9]|[12]\d|3[01])\2(?!0000)((?=(?:00(?:4[0-5]|[0-3]?\d)\x20BC)|(?:\d{4}(?!\x20BC)))\d{4}(?:\x20BC)?)(?:$|(?=\x20\d)\x20))?((?:(?:0?[1-9]|1[012])(?::[0-5]\d){0,2}(?:\x20[aApP][mM]))|(?:[01]\d|2[0-3])(?::[0-5]\d){1,2})?$/);

answered Jul 06 '16 at 18:10

Gustavo Rossi Muller

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While code often speaks for itself, answers that only contain code and have no textual explanation, get flagged for the review queues. You can avoid this by adding a sentence or two of explanation. – Will Jul 07 '16 at 03:32
Did not explant what function it included and make people confuse. – Tony Dong Sep 26 '16 at 22:53

regular expression to validate datetime format (MM/DD/YYYY)

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