Alexander Belopolsky added the comment: I've read this more carefully and I now understand the issue. Indeed, setting time.timezone or time.altzone has no effect on say time.strftime('%z'). I think this should be documented and the doc should refer to time.tzset() for a proper way to change these variables. As for making them read only, I don't think there is a non-hackish way to make module globals read-only. I also believe that rather than improving these variables we should encourage people to use datetime module's new timezone features because at almost any location on Earth timezone offset is not a constant and varies over time. ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue15941> _______________________________________