I am a little confused after having some very strange issues formatting dates and strings with the CultureInfo.InvariantCulture today with one of our applications.

One of our methods tries to parse a string as a date:

DateTime.Parse(myStringDate, CultureInfo.InvariantCulture);

If I passed in ‘28/05/2006′ this would throw a format exception. Why?

Another extremely weird thing would be if I had formatted a date using CultureInfo.InvariantCulture and then passed that as a parameter to a SQL query, the query would eventually time out.  Removing the InvariantCulture parameter and everything worked perfectly.

Very weird.  Any ideas?