Regex Tester & Validator

Validates dates in yyyy-mm-dd format for years 1900-2099, enforcing month-aware day limits: February accepts days 01-29 (allowing Feb 29 in any year), 31-day months (Jan, Mar, May, Jul, Aug, Oct, Dec) accept up to 31, and the remaining months up to 30. Commonly used for validating manual date entry in PHP forms. Note it does not strictly check leap years, so Feb 29 matches even in non-leap years.