Regex to validate date formats dd/mm/YYYY, dd-mm-YYYY, dd.mm.YYYY, dd mmm YYYY, dd-mmm-YYYY, dd/mmm/YYYY, dd.mmm.YYYY with Leap Year Support

Question

I need to validate a date string for the format dd/mm/yyyy with a regular expresssion.

This regex validates dd/mm/yyyy, but not the invalid dates like 31/02/4500:

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

What is a valid regex to validate dd/mm/yyyy format with leap year support?

Answer 1

The regex you pasted does not validate leap years correctly, but there is one that does in the same post. I modified it to take dd/mm/yyyy, dd-mm-yyyy or dd.mm.yyyy.

^(?:(?:31(/|-|.)(?:0?[13578]|1[02]))1|(?:(?:29|30)(/|-|.)(?:0?[13-9]|1[0-2])2))(?:(?:1[6-9]|[2-9]d)?d{2})$|^(?:29(/|-|.)0?23(?:(?:(?:1[6-9]|[2-9]d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00))))$|^(?:0?[1-9]|1d|2[0-8])(/|-|.)(?:(?:0?[1-9])|(?:1[0-2]))4(?:(?:1[6-9]|[2-9]d)?d{2})$

I tested it a bit in the link Arun provided in his answer and also here and it seems to work.

Edit February 14th 2019: I've removed a comma that was in the regex which allowed dates like 29-0,-11