Hello, Ian.

Do we understand you correctly that you pass date value as string to SQL Server query or stored proc? If you pass it as a SQL parameter then you don't need to convert it to string - you can just pass DateTime. If you are building SQL query dynamically, then programmatic approach you've been using is probably the right one. Although you may also try to change globalization settings in your application's web.config instead of Cassini's.

Also, could you please tell us if this problem is Cassini-specific? Please let us know if you ran your application under IIS and it had different behavior there compared to our Cassini?

Please let us know if this information has helped.

Best regards,
UltiDev Team.