private bool CheckTeacherTime(TeacherCourse aTeacherCourse)
        {
            aTeacherGateway = new TeacherGateway();
            ScheduleGateway aScheduleGateway = new ScheduleGateway();
            List <int>      coursesId        = new List <int>();

            coursesId = aTeacherGateway.GetTeacherAssignCoursesId(aTeacherCourse);
            List <Schedule> schedules = new List <Schedule>();

            schedules = aScheduleGateway.GetTeacherAllSchedules(coursesId);
            List <Schedule> currentScheduleList = new List <Schedule>();

            currentScheduleList = aScheduleGateway.GetCurrentCourseSchedules(aTeacherCourse);
            foreach (Schedule schedule in currentScheduleList)
            {
                foreach (Schedule aSchedule in schedules)
                {
                    if (schedule.DayId == aSchedule.DayId && ((schedule.StartTime <= aSchedule.StartTime && schedule.EndingTime >= aSchedule.StartTime) || (schedule.StartTime <= aSchedule.EndingTime & schedule.EndingTime >= aSchedule.EndingTime)))
                    {
                        return(true);
                    }
                }
            }
            return(false);
        }