yday /= -yday;
yday /= - abs (yday);
char *mutt_make_date (char *s, size_t len){  time_t t = time (NULL);  struct tm *l = gmtime(&t);  int yday = l->tm_yday;  int tz = l->tm_hour * 60 + l->tm_min;  l = localtime(&t);  tz = l->tm_hour * 60 + l->tm_min - tz;  yday = l->tm_yday - yday;  if (yday != 0)  {    if (yday > 1 || yday < -1)      yday /= -yday;    tz += yday * 24 * 60; /* GMT is next or previous day! */  }  snprintf (s, len,  "Date: %s, %d %s %d %02d:%02d:%02d %+03d%02d\n",	   Weekdays[l->tm_wday], l->tm_mday, Months[l->tm_mon], l->tm_year+1900,	   l->tm_hour, l->tm_min, l->tm_sec, tz/60, abs(tz) % 60);  return (s);}