DD_DAY_SHIFT
lastddate = ((days + 1) << DD_DAY_SHIFT)
days += ((dd & DD_DAY_MASK) >> DD_DAY_SHIFT) - 1;
| (1 << DD_DAY_SHIFT);
lastddate = ((days + 1) << DD_DAY_SHIFT)
| (1 << DD_DAY_SHIFT);