new_contents: # -*- coding: utf-8 -*-
  import datetime
  from sqlalchemy import Column, Date, Time
  
  
  class CalendarDbItem(object):
      date = Column(Date)
      time_start = Column(Time)
      time_end = Column(Time)
  
      @property
      def datetime_start(self):
          return datetime.datetime.combine(self.date, self.time_start)
  
      @property
      def datetime_end(self):
          return datetime.datetime.combine(self.date, self.time_end)
  
subject: Add CalendarDbItem to mozbase