Where a statute provides that it is to come into force or operation on a day or date to be fixed by the Governor by proclamation, or that it is not to come into force or operation until a day or date to be so fixed, any such proclamation—
(a) may apply to the whole or any part or parts or portion or portions or section or sections of the statute; and
(b) may be issued at different times as to any part or parts or portion or portions or section or sections of the statute.