HelenOS sources

days_since_epoch  263 uspace/lib/c/generic/time.c 	return days_since_epoch(tm->tm_year, tm->tm_mon, tm->tm_mday) *
days_since_epoch  280 uspace/lib/c/generic/time.c 	return floor_mod(days_since_epoch(year, mon, mday) + 4, 7);