One learns new things about time and stat tuples every day! Made a much cleaner patch which provides an extra named attribute (tm_gmtoff) whilst preserving the 9-tuple layout. Where no time zone support exists, tm_gmtoff is None; otherwise it's the GMT/UTC offset.

I had weird test issues with range(7) giving "TypeError: an integer is required" in the code employed (deep down) in test_strptime at some point during development, probably due to memory issues, so it might be worth checking that I've dealt properly with such things.
File Added: tm_gmtoff.diff