Javascript date regex DD/MM/YYYY

小开

最佳答案

You could take the regex that validates YYYY/MM/DD and flip it around to get what you need for DD/MM/YYYY:

/^(0?[1-9]|[12][0-9]|3[01])[\/\-](0?[1-9]|1[012])[\/\-]\d{4}$/

BTW - this regex validates for either DD/MM/YYYY or DD-MM-YYYY

P.S. This will allow dates such as 31/02/4899

小开

A regex is good for matching the general format but I think you should move parsing to the Date class, e.g.:

function parseDate(str) {
var m = str.match(/^(\d{1,2})\/(\d{1,2})\/(\d{4})$/);
return (m) ? new Date(m[3], m[2]-1, m[1]) : null;
}

Now you can use this function to check for valid dates; however, if you need to actually validate without rolling (e.g. "31/2/2010" doesn't automatically roll to "3/3/2010") then you've got another problem.

[Edit] If you also want to validate without rolling then you could add a check to compare against the original string to make sure it is the same date:

function parseDate(str) {
var m = str.match(/^(\d{1,2})\/(\d{1,2})\/(\d{4})$/)
, d = (m) ? new Date(m[3], m[2]-1, m[1]) : null
, nonRolling = (d&&(str==[d.getDate(),d.getMonth()+1,d.getFullYear()].join('/')));
return (nonRolling) ? d : null;
}

[Edit2] If you want to match against zero-padded dates (e.g. "08/08/2013") then you could do something like this:

function parseDate(str) {
function pad(x){return (((''+x).length==2) ? '' : '0') + x; }
var m = str.match(/^(\d{1,2})\/(\d{1,2})\/(\d{4})$/)
, d = (m) ? new Date(m[3], m[2]-1, m[1]) : null
, matchesPadded = (d&&(str==[pad(d.getDate()),pad(d.getMonth()+1),d.getFullYear()].join('/')))
, matchesNonPadded = (d&&(str==[d.getDate(),d.getMonth()+1,d.getFullYear()].join('/')));
return (matchesPadded || matchesNonPadded) ? d : null;
}

However, it will still fail for inconsistently padded dates (e.g. "8/08/2013").

小开

If you are in Javascript already, couldn't you just use Date.Parse() to validate a date instead of using regEx.

RegEx for date is actually unwieldy and hard to get right especially with leap years and all.

小开

Take a look from here https://www.regextester.com/?fam=114662

Use this following Regular Expression Details, This will support leap year also.

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])|(([1][26]|[2468][048]|[3579][26])00))))$/g;

Example

小开

Do the following change to the jquery.validationengine-en.js file and update the dd/mm/yyyy inline validation by including leap year:

"date": {
// Check if date is valid by leap year
"func": function (field) {
//var pattern = new RegExp(/^(\d{4})[\/\-\.](0?[1-9]|1[012])[\/\-\.](0?[1-9]|[12][0-9]|3[01])$/);
var pattern = new RegExp(/^(0?[1-9]|[12][0-9]|3[01])[\/\-\.](0?[1-9]|1[012])[\/\-\.](\d{4})$/);
var match = pattern.exec(field.val());
if (match == null)
return false;


//var year = match[1];
//var month = match[2]*1;
//var day = match[3]*1;
var year = match[3];
var month = match[2]*1;
var day = match[1]*1;
var date = new Date(year, month - 1, day); // because months starts from 0.


return (date.getFullYear() == year && date.getMonth() == (month - 1) && date.getDate() == day);
},
"alertText": "* Invalid date, must be in DD-MM-YYYY format"

小开

I use this function for dd/mm/yyyy format :

// (new Date()).fromString("3/9/2013") : 3 of september
// (new Date()).fromString("3/9/2013", false) : 9 of march
Date.prototype.fromString = function(str, ddmmyyyy) {
var m = str.match(/(\d+)(-|\/)(\d+)(?:-|\/)(?:(\d+)\s+(\d+):(\d+)(?::(\d+))?(?:\.(\d+))?)?/);
if(m[2] == "/"){
if(ddmmyyyy === false)
return new Date(+m[4], +m[1] - 1, +m[3], m[5] ? +m[5] : 0, m[6] ? +m[6] : 0, m[7] ? +m[7] : 0, m[8] ? +m[8] * 100 : 0);
return new Date(+m[4], +m[3] - 1, +m[1], m[5] ? +m[5] : 0, m[6] ? +m[6] : 0, m[7] ? +m[7] : 0, m[8] ? +m[8] * 100 : 0);
}
return new Date(+m[1], +m[3] - 1, +m[4], m[5] ? +m[5] : 0, m[6] ? +m[6] : 0, m[7] ? +m[7] : 0, m[8] ? +m[8] * 100 : 0);
}

小开

For people who needs to validate years earlier than year 1900, following should do the trick. Actually this is same as the above answer given by [@OammieR][1] BUT with years including 1800 - 1899.

/^(((0[1-9]|[12]\d|3[01])\/(0[13578]|1[02])\/((19|[2-9]\d)\d{2}))|((0[1-9]|[12]\d|3[01])\/(0[13578]|1[02])\/((18|[2-9]\d)\d{2}))|((0[1-9]|[12]\d|30)\/(0[13456789]|1[012])\/((19|[2-9]\d)\d{2}))|((0[1-9]|[12]\d|30)\/(0[13456789]|1[012])\/((18|[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))))$/

Hope this helps someone who needs to validate years earlier than 1900, such as 01/01/1855, etc.

Thanks @OammieR for the initial idea.

小开

((?=\d{4})\d{4}|(?=[a-zA-Z]{3})[a-zA-Z]{3}|\d{2})((?=\/)\/|\-)((?=[0-9]{2})[0-9]{2}|(?=[0-9]{1,2})[0-9]{1,2}|[a-zA-Z]{3})((?=\/)\/|\-)((?=[0-9]{4})[0-9]{4}|(?=[0-9]{2})[0-9]{2}|[a-zA-Z]{3})

Regex Compile on it

2012/22/Jan
2012/22/12
2012/22/12
2012/22/12
2012/22/12
2012/22/12
2012/22/12
2012-Dec-22
2012-12-22
23/12/2012
23/12/2012
Dec-22-2012
12-2-2012
23-12-2012
23-12-2012

小开

Try using this..

[0-9]{2}[/][0-9]{2}[/][0-9]{4}$

this should work with this pattern DD/DD/DDDD where D is any digit (0-9)

小开

I build this regular to check month 30/31 and let february to 29.

new RegExp(/^((0[1-9]|[12][0-9]|3[01])(\/)(0[13578]|1[02]))|((0[1-9]|[12][0-9])(\/)(02))|((0[1-9]|[12][0-9]|3[0])(\/)(0[469]|11))(\/)\d{4}$/)

I think, it's more simple and more flexible and enough full.

Perhaps first part can be contract but I Don't find properly.

小开

Scape slashes is simply use \ before / and it will be escaped. (\/=> /).

Otherwise you're regex DD/MM/YYYY could be next:

/^[0-9]{2}[\/]{1}[0-9]{2}[\/]{1}[0-9]{4}$/g

Explanation:

[0-9]: Just Numbers
{2} or {4}: Length 2 or 4. You could do {2,4} as well to length between two numbers (2 and 4 in this case)
[\/]: Character /
g : Global -- Or m: Multiline (Optional, see your requirements)
$: Anchor to end of string. (Optional, see your requirements)
^: Start of string. (Optional, see your requirements)

An example of use:

var regex = /^[0-9]{2}[\/][0-9]{2}[\/][0-9]{4}$/g;


var dates = ["2009-10-09", "2009.10.09", "2009/10/09", "200910-09", "1990/10/09",
"2016/0/09", "2017/10/09", "2016/09/09", "20/09/2016", "21/09/2016", "22/09/2016",
"23/09/2016", "19/09/2016", "18/09/2016", "25/09/2016", "21/09/2018"];


//Iterate array
dates.forEach(
function(date){
console.log(date + " matches with regex?");
console.log(regex.test(date));
});

Of course you can use as boolean:

if(regex.test(date)){
//do something
}

小开

This validates date like dd-mm-yyyy

([0-2][0-9]|(3)[0-1])(\-)(((0)[0-9])|((1)[0-2]))(\-)([0-9][0-9][0-9][0-9])

This can use with javascript like angular reactive forms

小开

It can be done like this for dd/mm/yyyy:

^(3[01]|[12][0-9]|0[1-9])/(1[0-2]|0[1-9])/[0-9]{4}$

For mm/dd/yy, mm/dd/yyyy, dd/mm/yy, and dd/mm/yyyy:

Allowing leading zeros to be omitted:

^[0-3]?[0-9]/[0-3]?[0-9]/(?:[0-9]{2})?[0-9]{2}$

Requiring leading zeros:

^[0-3][0-9]/[0-3][0-9]/(?:[0-9][0-9])?[0-9][0-9]$

For more details: https://www.oreilly.com/library/view/regular-expressions-cookbook/9781449327453/ch04s04.html