How do I convert (universal datetime) string to datetime in c#

Question

I am trying the following statement and it throws an error:

DateTime.ParseExact("Wed, 06 May 2015 11:08:00 PDT", "ddd, dd MMM yyyy HH:mm:ss GMT", null)

I even tried this and it did not work:

DateTime.ParseExact("Wed, 06 May 2015 11:08:00 PDT", "R", null)