EPOCH_WDAY
tmp->tm_wday = (int)((EPOCH_WDAY + days) % DAYSPERWEEK);
zic_t wday = ((EPOCH_WDAY + dayoff % DAYSPERWEEK + DAYSPERWEEK)
tmptr->tm_wday = (int)((EPOCH_WDAY + days) % DAYSPERWEEK);
tmp->tm_wday = (int)((EPOCH_WDAY + days) % DAYS_PER_WEEK);