GENERIC_DATE_PATTERN = "^((((0?[1-9]|[12]\d|3[01])\.(0?[13578]|1[02])\.((1[6-9]|[2-9]\d)?\d{2}))|((0?[1-9]|[12]\d|30)\.(0?[13456789]|1[012])\.((1[6-9]|[2-9]\d)?\d{2}))|((0?[1-9]|1\d|2[0-8])\.0?2\.((1[6-9]|[2-9]\d)?\d{2}))|(29\.0?2\.((1[6-9]|[2-9]\d)?(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00)|00)))|(((0[1-9]|[12]\d|3[01])(0[13578]|1[02])((1[6-9]|[2-9]\d)?\d{2}))|((0[1-9]|[12]\d|30)(0[13456789]|1[012])((1[6-9]|[2-9]\d)?\d{2}))|((0[1-9]|1\d|2[0-8])02((1[6-9]|[2-9]\d)?\d{2}))|(2902((1[6-9]|[2-9]\d)?(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00)|00))))$"
More info on Regular Expressions:
- http://www.codeproject.com/Articles/9099/The-30-Minute-Regex-Tutorial
- http://blogs.msdn.com/b/zainnab/archive/2008/03/11/regular-expression-webcast-series.aspx
- Regular Expression Language - Quick Reference
- Mastering Regular Expressions, by Jeffrey Friedl, Chapter 9, .NET is available on-line for free
