[Cumulative basis] C # calculates the time difference

  TimeSpan nowTime = new TimeSpan(DateTime.Now.Ticks);
                TimeSpan nextTime = new TimeSpan(nextDispatchert.RegBeginTime.Ticks);
                TimeSpan gapTime = nowTime.Subtract(nextTime).Duration();

　　

Min may be obtained by gapTime, hours, seconds, days