Regex Tester & Validator

Validates a full ISO 8601 date-time string including a timezone designator. It matches years 1900-2099, months 01-12, days 01-31, hours 00-23, minutes/seconds 00-59, followed by 'Z' (UTC) or a ±HH / ±HH:MM offset, where offset minutes are optional except after '-00'. Useful for validating datetime inputs in forms, APIs, and log parsing. Note it does not enforce per-month day limits (e.g., Feb 30) or fractional seconds.