On Fri, Aug 28, 2015 at 6:53 PM, Guido van Rossum <guido@python.org> wrote:
I'm not entirely sure why we didn't add this to the stdlib ages ago.

Maybe because tm_gmtoff was not added to time.struct_time until Python 3.3 [1] and was not available from the most of the C libraries at the time?

[1]: https://docs.python.org/3/library/time.html#time.struct_time