def advance_time_delta(timedelta):
 assert (not (utcnow.override_time is None))
 try:
  for dt in utcnow.override_time:
   dt += timedelta
 except TypeError:
  utcnow.override_time += timedelta

def advance_time_delta ( timedelta ) : assert ( not ( utcnow . override_time is None ) ) try : for dt in utcnow . override_time : dt += timedelta except TypeError : utcnow . override_time += timedelta
advance overridden time using a datetime .