Date regex

Date regex

Date regular expressions can be used to validate if a string has a valid date format and to extract a valid date from a string.

JavaScript
JavaScript
Python
Python
Java
Java
C#
C#
PHP
PHP

Simple date regex (DD/MM/YYYY)

Below is a simple regex to validate the string against a date format (D/M/YYYY or M/D/YYYY). This however does not guarantee that the date would be valid (read about moment.js below). You can also replace \/ with a separator you need.

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

Test it!
/^[0-9]{1,2}\/[0-9]{1,2}\/[0-9]{4}$/

True

False

Enter a text in the input above to see the result

Example code in Javascript:

var dateRegex = /^[0-9]{1,2}\/[0-9]{1,2}\/[0-9]{4}$/;
// Validate date
var dateString = '12/12/2022';
dateRegex.test(dateString); // Returns true

// Extract date from a string
var dateRegexG = /[0-9]{1,2}\/[0-9]{1,2}\/[0-9]{4}/g;
'I\'m on vacation from 1/18/2021 till 1/29/2021'.match(dateRegexG); // returns ['1/18/2021', '1/29/2021']

ISO 8061 date regex (e.g. 2021-11-04T22:32:47.142354-10:00)

The ISO 8061 is an international standard for exchanging and serializing date and time data. For validating the format of ISO 8061 date and time and for extracting it a following regular expression could be used:

/^(?:\d{4})-(?:\d{2})-(?:\d{2})T(?:\d{2}):(?:\d{2}):(?:\d{2}(?:\.\d*)?)(?:(?:-(?:\d{2}):(?:\d{2})|Z)?)$/

Test it!
/^(?:\d{4})-(?:\d{2})-(?:\d{2})T(?:\d{2}):(?:\d{2}):(?:\d{2}(?:\.\d*)?)(?:(?:-(?:\d{2}):(?:\d{2})|Z)?)$/

True

False

Enter a text in the input above to see the result

Example code in Javascript:

var ISOregex = /^(?:\d{4})-(?:\d{2})-(?:\d{2})T(?:\d{2}):(?:\d{2}):(?:\d{2}(?:\.\d*)?)(?:(?:-(?:\d{2}):(?:\d{2})|Z)?)$/;
// Validate ISO date
var dateString = '2021-11-04T22:32:47.142354-10:00';
ISOregex.test(dateString); // Returns true

// Extract date and time from example server log string
var ISOregexG = /(?:\d{4})-(?:\d{2})-(?:\d{2})T(?:\d{2}):(?:\d{2}):(?:\d{2}(?:\.\d*)?)(?:(?:-(?:\d{2}):(?:\d{2})|Z)?)/g;
'2017-05-23T15:02:27Z | WARN | Record not found\n2018-05-23T15:02:28Z | WARN | Project with the id ’53’ was not found'.match(ISOregexG); // returns ['2017-05-23T15:02:27Z', '2018-05-23T15:02:28Z']

Test it!

True

False

Enter a text in the input above to see the result

Notes on date string regex validation

While there are some regular expressions that allow more complex date validations, it is usually better to validate dates using special date and time libraries. For example, in Javascript moment.js library can be used for these purposes. In this case, the validation will look like this:

var date = moment(yourDateString);
date.isValid(); // returns true if variable yourDateString contains a valid date and time string