sub_ddmmss
sub_ddmmss (n1, n0, n1, n0, d1, d0);
sub_ddmmss (n1, n0, n1, n0, 0, d0);
sub_ddmmss (n1, n0, r, n2, n1, n0);
sub_ddmmss (_xh, _r, (nh), (nl), _xh, _xl); \
sub_ddmmss (_xh, _r, _xh, _r, 0, (d)); \
sub_ddmmss (_xh, _r, _xh, _r, 0, (d)); \
#if !defined (sub_ddmmss)
sub_ddmmss (n1, n0, n1, n0, 0, d0);
sub_ddmmss (n1, n0, r, 0, n1, n0);