      ...
      2015-06-15 00:00:00 2
      2015-12-25 00:00:00 1
      >>> experiments = Experiment.objects.annotate(
      ...    start_day=Trunc('start_time', 'day', output_field=DateTimeField())
      ... ).filter(start_day=datetime(2015, 6, 15))
      >>> for exp in experiments:
      ...     print(exp.start_time)
      ...
      2015-06-15 14:30:50.000321
 
</s> remove     ...     print(exp.start_time)
 </s> add     ...     print(exp.start_datetime) </s> remove     ...    start_day=Trunc('start_time', 'day', output_field=DateTimeField())
 </s> add     ...    start_day=Trunc('start_datetime', 'day', output_field=DateTimeField()) </s> remove     ...    month=TruncMonth('start_time', tzinfo=melb)).values('month').annotate(
 </s> add     ...    month=TruncMonth('start_datetime', tzinfo=melb)).values('month').annotate( </s> remove     >>> Experiment.objects.create(start_time=datetime(2015, 6, 15, 14, 30, 50, 321))
    >>> Experiment.objects.create(start_time=datetime(2015, 6, 15, 14, 40, 2, 123))
    >>> Experiment.objects.create(start_time=datetime(2015, 12, 25, 10, 5, 27, 999))
 </s> add     >>> Experiment.objects.create(start_datetime=datetime(2015, 6, 15, 14, 30, 50, 321))
    >>> Experiment.objects.create(start_datetime=datetime(2015, 6, 15, 14, 40, 2, 123))
    >>> Experiment.objects.create(start_datetime=datetime(2015, 12, 25, 10, 5, 27, 999)) </s> remove     ...    start_time__year=Extract('end_time', 'year')).count()
 </s> add     ...    start_datetime__year=Extract('end_datetime', 'year')).count()
    ...    start_day=Trunc('start_datetime', 'day', output_field=DateTimeField())
      ...
      2015-06-15 00:00:00 2
      2015-12-25 00:00:00 1
      >>> experiments = Experiment.objects.annotate(
    ...    start_day=Trunc('start_datetime', 'day', output_field=DateTimeField())
      ... ).filter(start_day=datetime(2015, 6, 15))
      >>> for exp in experiments:
      ...     print(exp.start_time)
      ...
      2015-06-15 14:30:50.000321
keep keep keep keep replace keep keep keep keep keep
 Refs #25774 -- Adjusted datetime database function docs field names. 
docs/ref/models/database-functions.txt