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Timing Functions on Cygwin

I have trouble with timing functions(time(), localtime(),
tzset(), mktime()) on Cygwin using gcc compiler.

I wrote a simple program attached.

It basicly converts the value from time()(call it A) to tm structure, then
converts this tm back to a value in seconds using tzset() and
mktime()(call it B).  A and B are supposed to be equal.  Cygwin gives me a
6 hours difference(I am in Central Time Zone), while other systems(I tried
IRIX, Linux, Sun OS) work well.  

Hope you can give me a hint!

/* test timing:
 *    get local time from time() and localtime(),
 *    convert to time in seconds by mktime(),
 *    supposed to get same values.  
#include <stdio.h>
#include <time.h>
#include <sys/time.h>

  struct tm *tm;
  time_t now, the_time;

  /*get current time in seconds.*/
  now = time(0);
  /* convert to tm structure */
  tm = localtime(&now);  

  /*adjust to local time zone and daylight saving time */
  /*convert tm structure to time in seconds.  Cygwin returns Greenwich time 
    here while other systems return local time. */
  the_time = mktime(tm);

  fprintf(stderr, "tm->tm_isdst=%d\n", tm->tm_isdst); 
  fprintf(stderr, "now=%d,\nthe_time=%d,\nnow - the_time=%d\n", now, the_time,

  return 0;
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