private bool DayIsEmpty(Day day)
        {
            if (schedule == null || schedule.periods == null || schedule.periods.Length == 0)
            {
                return(true);
            }

            int emptyPeriodCount = 0;
            int periodCount      = schedule.periods.Length;

            for (int i = 0; i < periodCount; i++)
            {
                PeriodGroup   period = schedule.periods[i];
                ScheduleEntry entry  = period.GetEntry(day);

                if (entry == null)
                {
                    continue;
                }

                if (entry.isEmpty)
                {
                    emptyPeriodCount++;
                }
            }

            return(emptyPeriodCount >= periodCount);
        }
    public void ViewEntry(Day day)
    {
        ScheduleEntry entry = period.GetEntry(day);

        SetEntry(entry);
    }