/// <see cref="AppointmentDAL.GetAppointmentInDateRange(DateTime, DateTime)"/>
 public List <AppointmentDTO> GetAppointmentsInDateRange(DateTime startDate, DateTime endDate)
 {
     if (startDate == null || endDate == null)
     {
         throw new ArgumentNullException("startDate and endDate cannot be null");
     }
     return(AppointmentDAL.GetAppointmentInDateRange(startDate, endDate.AddDays(1)));
 }