Regular Expression to match valid dates

Question

I\'m trying to write a regular expression that validates a date. The regex needs to match the following

• M/D/YYYY
• MM/DD/YYYY
• Single digit mon

Answer 1

If you're going to insist on doing this with a regular expression, I'd recommend something like:

( (0?1|0?3| <...> |10|11|12) / (0?1| <...> |30|31) |
  0?2 / (0?1| <...> |28|29) ) 
/ (19|20)[0-9]{2}

This might make it possible to read and understand.