Function update_tm

date.c:1080–1101

* Relative time update (eg "2 days ago"). If we haven't set the time * yet, we need to set it from current time. * * The tm->tm_mday field has an additional logic of using negative values * for date adjustments: -2 means yesterday and -3 the day before that, * and so on. The idea is to defer such adjustments until we are sure * there's no explicit mday specification in the approxidate stri

 * there's no explicit mday specification in the approxidate string.
 */
static time_t update_tm(struct tm *tm, struct tm *now, time_t sec)
{
	time_t n;

	if (tm->tm_mday < 0) {
		int offset = tm->tm_mday + 1;
		if (sec == 0 && offset < 0)
			sec = -offset * 24*60*60;
		tm->tm_mday = now->tm_mday;
	}
	if (tm->tm_mon < 0)
		tm->tm_mon = now->tm_mon;
	if (tm->tm_year < 0) {
		tm->tm_year = now->tm_year;
		if (tm->tm_mon > now->tm_mon)
			tm->tm_year--;
	}

	n = mktime(tm) - sec;
	localtime_r(&n, tm);
	return n;
}

/*
 * Do we have a pending number at the end, or when