^(?:\d{4}\-\d{2}\-\d{2}[Tt ]\d{2}:\d{2}(?::\d{2}(?:\.\d+)?)?(?:(?:[+-]\d{2}:?\d{2}|[Zz]))?|\d{4}\d{2}\d{2}[Tt]\d{2}\d{2}\d{2}(?:(?:[+-]\d{4}|[Zz]))?)$