code: def make_all_day(self):
          
          if self.all_day:
              # Do nothing if we already are a all day event
              return
  
          begin_day = self.begin.floor('day')
          end_day = self.end.floor('day')
  
          self._begin = begin_day
  
          # for a one day event, we don't need a _end_time
          if begin_day == end_day:
              self._end_time = None
          else:
              self._end_time = end_day + timedelta(days=1)
  
          self._duration = None
          self._begin_precision = 'day'
docs: Transforms self to an all-day event.
  
          The event will span all the days from the begin to the end day.