// use Day function to get day of year, need to declare first
int Day(double date, int option = 1);  // option = 1 for month day, = 2 for year day


void testSYSTEMTIME_TM()
{
	SYSTEMTIME systime;
	TM t;
	GetSystemTime(&systime);
	systemtime_to_tm(&t, &systime);

	double lpdDate;
	SystemTimeToJulianDate(&lpdDate, &systime);  // get Julian date from SYSTEMTIME
	int nYDay = Day(lpdDate, 2);  // get day of year
	if(nYDay >= 0)
		t.tm_yday = nYDay;  // set tm_yday
}