перменая DateTime

    public class WorkingTime
    {
        int workTimeHour;
        double workTimeMin;
 
        private DateTime alarm = new DateTime();        
        
        
 
        public WorkingTime(int WorkTimeHour,double WorkTimeMin)
        {            
            workTimeHour = WorkTimeHour;
            workTimeMin = WorkTimeMin;
            alarm = DateTime.Now;
            alarm.AddHours(workTimeHour);
            alarm.AddMinutes(workTimeMin);            
        }

    class Program
    {
        static void Main(string[] args)
        {
            WorkingTime wt = new WorkingTime(30,30);
            Console.WriteLine(wt.ToString());
 
            Console.WriteLine(wt.GetWTH.ToString());
 
            Console.WriteLine(DateTime.Now-wt.Alarm);
 
            Console.ReadKey();
        }
    }

alarm.AddHours(30);

wt.GetWTH.ToString(); //что за WTH?

DateTime.Now-wt.Alarm

this.workTimeHour = WorkTimeHour;
this.workTimeMin = WorkTimeMin;

alarm=alarm.AddHours(workTimeHour);