Interfaces.objects.all()
.annotate(
  age = (datetime.utcnow() - F('timestamp')), # 0:00:08.535704
  age2 = Epoch(datetime.utcnow() - F('timestamp')), # 8.535704
  # age3 = int(Epoch(datetime.utcnow() - F('timestamp'))/300),
  current_time=Value(str(datetime.utcnow()),
                       output_field=null_char_field),
)
.order_by('age','ip')