#ifndef G_OS_WIN32 /* Declared properly in time.h already */
extern char *tzname[2];
#ifndef __BSD_VISIBLE
extern long timezone;
#endif
extern int daylight;
get_local_timezone()
{
icaltimezone *zone;
long offset;
#ifdef __BSD_VISIBLE
time_t tt;
struct tm tm;
tzset();
zone = icaltimezone_get_builtin_timezone_from_offset (-timezone, tzname[0]);
localtime_r (&tt, &tm);
offset = tm.tm_gmtoff;
#else
offset = -timezone;
zone = icaltimezone_get_builtin_timezone_from_offset (offset, tzname[0]);
return zone;
}