DateTime type query

Hi All,

I'm having some problems updating my sql server table from my C# app. The table has a single DateTime column which is updated from the app using the query built using:-

oleDbCommand.CommandText = String.Format("UPDATE _User SET LastLoginDate={'0'}", DateTime.Now);

This query ran fine until today when it started failing saying that the datetime is invalid. The DateTime.Now returns (for me) a date in the format dd/mm/ccyy, for today that's 13/05/2004. The failure suggests that this is in the wrong format so I assume that at some point is believes that this date is in mm/dd/2004 format, for which 13/05/2004 is invalid and so it fails, which would explain why it's worked for the last week.

I'm pretty new to C# and I'm obviously missing some date formating trick somewhere. Could someone help? PLEASE!

Cheers

dex