private boolean timeConflict(Request oldRequest, Request newRequest)
   {
      int orStartTime = oldRequest.getDate().get(Calendar.HOUR_OF_DAY);
      int orEndTime = oldRequest.getDate().get(Calendar.HOUR_OF_DAY) + oldRequest.getDuration() / 60;
      int nrStartTime = newRequest.getDate().get(Calendar.HOUR_OF_DAY);
      int nrEndTime = newRequest.getDate().get(Calendar.HOUR_OF_DAY) + newRequest.getDuration() / 60;
      
      if ((newRequest.getDate().get(Calendar.DAY_OF_MONTH) == oldRequest.getDate().get(Calendar.DAY_OF_MONTH))
            && ((nrStartTime < orEndTime) && (nrStartTime >= orStartTime)))
            return true;
      if ((newRequest.getDate().get(Calendar.DAY_OF_MONTH) == oldRequest.getDate().get(Calendar.DAY_OF_MONTH))
            && ((nrEndTime > orStartTime) && (nrEndTime <= orEndTime)))
            return true;
            
         return false;
   }