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