Paul Martin <greatestloginnamee...@gmail.com> added the comment:
The difference between the two is the difference between your local time and utc. datetime.now(timezone.utc) This returns the current time in utc and is timezone aware. So the timestamp can figure out the seconds since epoch taking into account the timezone. datetime.utcnow() Returns the current utc time but is not timezone aware. When timestamp method is run, it is interpreted as a local timestamp. This is explained in the docs but perhaps it should be made clearer that datetime.utcnow().timestamp() is incorrect and would cause bugs. I'm not sure about changing the behaviour of utcnow to return a timezone-aware dt as is it could cause hard to detect bugs in existing code. But I did have issues recently where I was using utcnow until I went back and read the docs and changed to datetime.now(timezone.utc). So it's probably a common trap to fall into. >From the docs: " Naive datetime instances are assumed to represent local time # Note There is no method to obtain the POSIX timestamp directly from a naive datetime instance representing UTC time. If your application uses this convention and your system timezone is not set to UTC, you can obtain the POSIX timestamp by supplying tzinfo=timezone.utc: timestamp = dt.replace(tzinfo=timezone.utc).timestamp() or by calculating the timestamp directly: timestamp = (dt - datetime(1970, 1, 1)) / timedelta(seconds=1)" Warning Because naive datetime objects are treated by many datetime methods as local times, it is preferred to use aware datetimes to represent times in UTC. As such, the recommended way to create an object representing the current time in UTC is by calling datetime.now(timezone.utc). " ---------- nosy: +primal _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue44663> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
