Gets the local time zone label and offset from GMT, given utc.

    Format

      #include <utc.h>

      int utc_localzone(*tzname, tzlen, *tdf, *isdst, *utc)

         char *tzname;
         size_t tzlen;
         long *tdf;
         int *isdst;
         const utc_t *utc;

      #include <utc.h>

      int utc_localzone(*tzname, tzlen, *tdf, *isdst, *utc)