Regex Editor & Tester

This regular expression matches a date format intended for DD/MM/YYYY structures. It validates the day (01-31) and a 4-digit year from 1000 to 9999. However, the month portion ([01][12]) only matches 01, 02, 11, and 12, missing most months. It is used for validating user input in forms, though its month validation logic is notably flawed.