adjyear
if (!adjyear(t, '+', (t->tm_mon + val) / 12, 0))
if (!adjyear(t, '-', val / 12, 0))
if (!adjyear(t, '-', 1, 0))
if (!adjyear(t, type, val, 1))
if (!adjyear(t, type, val, 1))
if (!adjyear(t, type, val, 1))