ckd_sub
# if defined ckd_add && defined ckd_sub
? ckd_sub(&result->tm_year,
# ifdef ckd_sub
v = ckd_sub(&offdiff, mytm.TM_GMTOFF, yourtm.TM_GMTOFF);
#ifdef ckd_sub
return ckd_sub(tp, *tp, j);