C# DateTime format question

I'm trying to globalize my C# application. I need to convert dates from one culture to another as in the example below. 10/12/2008? ? ? which means October 12 2008 in American format, en-US I need this converted to 12.10.2008 which is European format or Turkish and vice versa the problem is with / or . and month and day switching places What is the C# function for this purpose?