+ tm->tm_mday); tm->tm_wday = wday;
+ tm->tm_mday - 1); tm->tm_wday = wday % 7;
day_of_the_week (struct tm *tm){  /* We know that January 1st 1970 was a Thursday (= 4).  Compute the     the difference between this data in the one on TM and so determine     the weekday.  */  int corr_year = tm->tm_mon >= 2 ? tm->tm_year : tm->tm_year - 1;  int wday = (-473	      + (365 * (tm->tm_year - 1970))	      + (corr_year / 4)	      - ((corr_year / 4) / 25) + ((corr_year / 4) % 25 < 0)	      + (((corr_year / 4) / 25) / 4)	      + __mon_yday[0][tm->tm_mon]	      + tm->tm_mday);  tm->tm_wday = wday;}