code: def get_hours_for_week(self, week_start=None):
          
          week_start = week_start if week_start else self.week_start
          week_end = week_start + relativedelta(days=7)
  
          return ProjectHours.objects.filter(
              week_start__gte=week_start, week_start__lt=week_end)
docs: Gets all ProjectHours entries in the 7-day period beginning on
          week_start.