Community Patterns

1

Date - Extract & Validate - Fully tested - Format YYYY-MM-DD (dynamic parts separator / can use a different separator)

Created·2020-11-20 19:31
Flavor·ECMAScript (JavaScript)
A fully tested regex that extracts and validates date parts using named capturing groups. \ Validations: Year must be preceded by nothing or a non-digit character Year must have 4 digits Month must be between 01 and 12 Month must have 2 digits Day must be between 01 and the maximum number of days for the month (e.g. february can't have more than 29 days) Day must have 2 digits Day must be followed by nothing or a non-digit character Separator must be any single character that is not a space or an alphanumeric character Separator must be the same between each date part \ Capturing groups: | # | Name | Description | |:-:|:-------:|-------------------------------------| | 1 | year | 4 digits of the year | | 2 | sep | Date parts separator | | 3 | month | 2 digits of the month | | 4 | day | 2 digits of the date (day of month) | \ Example usage: let match = regex.exec('2020-11-22') console.log('year: %s, month: %s, day: %s', match.groups.year, match.groups.month, match.groups.day) // year: 2020, month: 11, day: 22 \ Compatibility: (updated 2020-11-20) Chrome >= 64 Edge >= 79 Firefox >= 78 IE incompatible (lookbehind assertions & named capture groups not supported) Opera >= 51 Safari incompatible (lookbehind assertions not supported) NodeJS >= 10.0.0 See regex compatibility table. \ Note: does not validate leap years (not really possible in regex)
Submitted by Elie Grenon (DrunkenPoney) <elie.grenon.1@gmail.com>

Community Library Entry

0

Regular Expression
Created·2015-12-11 14:54
Flavor·PCRE (Legacy)

/
^(?:(?:(?:(3)\.?([01]2))\.?(\d{1,4})?)|(?:(3)\.?(1)\.?([469]\d?))|([1-2][0-9]|0?[1-9])\.?(?:(1[0-2]|0?[1-9])\.?(\d{1,4})?|(0)?)|(?:(31)\.?(?:(?:(0?[13578]|1[02])\.?(\d{1,4})?)|(0)?))|(?:(30)\.?(?:(?:(0?[13456789]|1[0-2])\.?(\d{1,4})?)|(0)?))|([0-9]))$
/
gm
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Description

this regex is able to validate a date (format dd.mm.yyyy) in every state of user typing. i use it to ensure that the user isn't able to type in an invalid date at all (except from a leap year check which is done afterwards)

The regex also makes assumptions of 'missed' separators so 1234 is captured in groups which can then be transformed to \1.\2.\3 -> 12.3.4

It was intensively but not exhaustivly tested

Submitted by anonymous