if (! compute_change (&tz_rules[0], 1900 + tm->tm_year) ||
! compute_change (&tz_rules[1], 1900 + tm->tm_year))
return 0;
+ /* We have to distinguish between northern and southern hemisphere.
+ For the later the daylight saving time ends in the next year.
+ It is easier to detect this after first computing the time for the
+ wrong year since now we simply can compare the times to switch. */
+ if (tz_rules[0].change > tz_rules[1].change
+ && ! compute_change (&tz_rules[1], 1900 + tm->tm_year + 1))
+ return 0;
__daylight = tz_rules[0].offset != tz_rules[1].offset;
__timezone = -tz_rules[0].offset;