Regex validate correct ISO8601 date string with time

by

Based on an earlier answer of mine, you could do this and be pretty darn strict:

^(?:[1-9]\d{3}-(?:(?:0[1-9]|1[0-2])-(?:0[1-9]|1\d|2[0-8])|(?:0[13-9]|1[0-2])-(?:29|30)|(?:0[13578]|1[02])-31)|(?:[1-9]\d(?:0[48]|[2468][048]|[13579][26])|(?:[2468][048]|[13579][26])00)-02-29)T(?:[01]\d|2[0-3]):[0-5]\d:[0-5]\d(?:Z|[+-][01]\d:[0-5]\d)$

Regular expression visualization

Debuggex Demo

Slightly monstrous but it checks for valid dates including leap-year (Proleptic Gregorian), works for years 1000-9999, checks for invalid times like 25:30 or 21:94 and a maximum UTC offset of +/-19:59 (or a Z).

(right now more than +14:00 or -12:00 doesn’t happen, but it might in the future).

For completion: This answer only supports a subset of the ISO8601 standard based on the examples OP gave. Which is the extended notation with seconds in the time section and minutes in the UTC offset. For brevity it does not support basic notation where dashes and colons are omitted, or the omitting of minutes in the UTC offset or the smallest unit. Nor is there support for ordinal dates (day-of-year) or year-week-dayofweek notations.

An extended version of the regex that supports basic notation, ordinal and the omitting of seconds / UTC-offset minutes lives here.

More Related Contents:

  1. Regex lookahead, lookbehind and atomic groups
  2. How to match multiple occurrences of a substring
  3. Find and kill a process in one line using bash and regex
  4. Regular expression to match standard 10 digit phone number
  5. Regex: matching up to the first occurrence of a character
  6. How can I validate an email address using a regular expression?
  7. Convert a char to upper case using regular expressions (EditPad Pro)
  8. How to check if a line is blank using regex
  9. Match linebreaks – \n or \r\n?
  10. Notepad++ incrementally replace
  11. How would I import YouTube Likes and Dislikes and a ratio from YouTube onto Google Sheets? [closed]
  12. What is the complexity of regular expression?
  13. What does ?= mean in a regular expression?
  14. Regular Expressions with repeated characters
  15. Why do ^ and $ not work as expected?
  16. Is there an online RegexBuddy-like regular expression analyzer? [closed]
  17. Regular Expression Match to test for a valid year
  18. Regex that does not allow consecutive dots
  19. How can I insert a tab character with sed on OS X?
  20. Searching for all variations of hyphens and dashes in Regex
  21. How do I remove all non-ASCII characters with regex and Notepad++?
  22. “Unknown escape sequence” error in Go
  23. Lazy quantifier {,}? not working as I would expect
  24. How do I use a new-line replacement in a BSD sed?
  25. Test for numeric elements in a character string
  26. Replace string only once with php preg_replace
  27. How to change date format in sed?
  28. Redirect all traffic to root of another domain
  29. ignoring changes matching a string in git diff
  30. Regex allow digits and a single dot

Leave a Comment