@staticmethod
  def _GetPreviousDateTime(t, target_time):

    date = t.date()
    while True:
      result = IntervalTimeSpecification._CombineDateAndTime(date, target_time)
      if result <= t:
        return result
      date -= datetime.timedelta(days=1)
Generates the expected results, be careful to double check the results
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/cron/groctimespecification.py/IntervalTimeSpecification._GetPreviousDateTime--crossover with--dataset/ETHPy150Open duerrp/pyexperiment/tests/test_examples.py/generate_expected