If you try to convert datetime objects to seconds since epoch and back
it will not work since the microseconds get lost:

>>> dt = datetime(2008, 5, 1, 13, 35, 41, 567777)
>>> seconds = mktime(dt.timetuple())
>>> datetime.fromtimestamp(seconds) == dt
False

Current fix is to do
>>> seconds += (dt.microsecond / 1000000.0)
>>> datetime.fromtimestamp(seconds) == dt
True