TSecTm TSecTm::Round(const TTmUnit& TmUnit) const {
  if (TmUnit == tmu1Sec) { return *this; }
  struct tm Time;
  IAssert(IsDef() && GetTmStruct(AbsSecs(), Time));
  switch (TmUnit) {
    case tmu1Min : return TSecTm(Time.tm_year+1900, Time.tm_mon+1, Time.tm_mday, Time.tm_hour, Time.tm_min, 0);
    case tmu10Min : return TSecTm(Time.tm_year+1900, Time.tm_mon+1, Time.tm_mday, Time.tm_hour, 10*(Time.tm_min/10), 0);
    case tmu15Min : return TSecTm(Time.tm_year+1900, Time.tm_mon+1, Time.tm_mday, Time.tm_hour, 15*(Time.tm_min/15), 0);
    case tmu30Min : return TSecTm(Time.tm_year+1900, Time.tm_mon+1, Time.tm_mday, Time.tm_hour, 30*(Time.tm_min/30), 0);
    case tmu1Hour : return TSecTm(Time.tm_year+1900, Time.tm_mon+1, Time.tm_mday, Time.tm_hour, 0, 0);
    case tmu2Hour : return TSecTm(Time.tm_year+1900, Time.tm_mon+1, Time.tm_mday, 2*(Time.tm_hour/2), 0, 0);
    case tmu4Hour : return TSecTm(Time.tm_year+1900, Time.tm_mon+1, Time.tm_mday, 4*(Time.tm_hour/4), 0, 0);
    case tmu6Hour : return TSecTm(Time.tm_year+1900, Time.tm_mon+1, Time.tm_mday, 6*(Time.tm_hour/6), 0, 0);
    case tmu12Hour : return TSecTm(Time.tm_year+1900, Time.tm_mon+1, Time.tm_mday, 12*(Time.tm_hour/12), 0, 0);
    case tmuDay : return TSecTm(Time.tm_year+1900, Time.tm_mon+1, Time.tm_mday, 0, 0, 0);
    case tmuMonth : return TSecTm(Time.tm_year+1900, Time.tm_mon+1, 1, 0, 0, 0);
    case tmuYear : return TSecTm(Time.tm_year+1900, 1, 1, 0, 0, 0);
    case tmuWeek : { int dd=1, mm=1, yy=1;
      // week starts on Thursday, since 1.1.1970 is Thursday
      const int Day = TJulianDate::GetJulianDateN(Time.tm_mday, Time.tm_mon+1, 1900+Time.tm_year);
      TJulianDate::GetCalendarDate(3+7*(Day/7), dd, mm, yy);  return TSecTm(yy, mm, dd, 0, 0, 0); }
    default : Fail;
  }
  return TSecTm();
}

void TSecTm::GetComps(int& Year, int& Month, int& Day, int& Hour, int& Min, int& Sec) const {
  struct tm Tm;
  EAssert(IsDef() && GetTmStruct(AbsSecs(), Tm));
  Year = Tm.tm_year+1900;
  Month = Tm.tm_mon+1;
  Day = Tm.tm_mday;
  Hour = Tm.tm_hour;
  Min = Tm.tm_min;
  Sec = Tm.tm_sec;
}