Question

On the client side, I’m validating strings that will be pushed to the .NET framework and I need to know what formats will be valid and recognized by .NET Framework.

http://msdn.microsoft.com/en-us/library/1k1skd40.aspx lists the formats recognized but doesn’t answer all of my questions.

For Date:
Are single digit day/month valid?
Are 2 digit years valid?

For Time:
What formats for am/pm are valid? Possible strings I can see are: (‘a’,’p’,’ a’,’ p’,’am’,’pm’,’ am’,’ pm’)

Answer 1

.NET can parse dates with single day/month and 2 digit years without a problem.

You need to use a custom format string for that.

DateTime.ParseExact("9/1/12", "d/M/yy", 
                    CultureInfo.InvariantCulture,
                    DateTimeStyles.None)

If you want to test for multiple formats, you can pass an array of format strings as the second parameter:

DateTime.ParseExact("9/1/12", new [] { "d/M/yy", "dd/MM/yyyy" } 
                    CultureInfo.InvariantCulture,
                    DateTimeStyles.None)