code: public long setDate(long year, long month, long day)
    {
      year += (long) Math.floor(month / 12.0);
      month -= (long) 12 * Math.floor(month / 12.0);
  
      _year = year;
      _month = month;
      _dayOfMonth = day - 1;
  
      calculateJoin();
      calculateSplit(_localTimeOfEpoch);
  
      return _localTimeOfEpoch;
    }
docs: Sets date in the local time.
  
  @param year
  @param month where January = 0
  @param day day of month where the 1st = 1