def pig_properties(self):
        return {}
Returns the latest datetime <= 't' that has the time target_time.
dataset/ETHPy150Open spotify/luigi/luigi/contrib/pig.py/PigJobTask.pig_properties--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/cron/groctimespecification.py/IntervalTimeSpecification._GetPreviousDateTime