makedate: wrong timezone offset if DST rules changed this year (
issue2511)
Python's time module sets timezone and altzone based on UTC offsets of
two dates: first and middle day of the current year. This approach
doesn't work on a year when DST rules change.
For example Russia abandoned winter time this year, so the correct UTC
offset should be +4 now, but time.timezone returns 3 hours difference
because that's what it was on 01.01.2011.
Related python issue: http://bugs.python.org/
issue1647654