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From: Archie Cobbs <archie@whistle.com>
Message-Id: <199608012340.QAA03973@bubba.whistle.com>
Subject: mktime(3) bug?
To: freebsd-questions@freebsd.org
Date: Thu, 1 Aug 1996 16:40:51 -0700 (PDT)
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Hi,

I'm confused about mktime(3) .. from the man page it appears that
it should ignore the current timezone of the machine its running
on, instead getting this information directly from the argument.
In practice, however, it seems to ignore the tm_gmtoff field completely.

Is this a mktime, a man page, or a reading comprehension bug? :-)

Example:

    #include <stdio.h>
    #include <stdlib.h>
    #include <time.h>

    main()
    {
      struct tm	tm;
      time_t	sec;

      memset(&tm, 0, sizeof(tm));
      tm.tm_mday = 1;
      tm.tm_year = 2;	/* replace with 1 and mktime() fails */

      sec = mktime(&tm);
      printf("seconds = %lu -> %s", sec, asctime(gmtime(&sec)));

      tm.tm_gmtoff = 3600;
      sec = mktime(&tm);
      printf("seconds = %lu -> %s", sec, asctime(gmtime(&sec)));
    }

On my machine (in California), I get this output:

    seconds = 2149079296 -> Wed Jan  1 08:00:00 1902
    seconds = 2149079296 -> Wed Jan  1 08:00:00 1902

Also, setting tm_year to 1 causes mktime() to fail.. why?

Thanks,
-Archie

___________________________________________________________________________
Archie L. Cobbs, archie@whistle.com  *  Whistle Communications Corporation