public void scheduleAtFixedRate(TimerTask task,Date when,long period){
  if (period <= 0 || when.getTime() < 0) {
    throw new IllegalArgumentException();
  }
  long delay=when.getTime() - System.currentTimeMillis();
  scheduleImpl(task,delay,period,true);
}

public void scheduleAtFixedRate ( TimerTask task , Date when , long period ) { if ( period <= 0 || when . getTime ( ) < 0 ) { throw new IllegalArgumentException ( ) ; } long delay = when . getTime ( ) - System . currentTimeMillis ( ) ; scheduleImpl ( task , delay , period , true ) ; }
schedule a task for repeated fixed - rate execution after a specific time has been reached .
