If:
(a) the Secretary or a person's employer (the payer ) is required to pay an instalment to the person on the payday for an instalment for a later instalment period; and
(b) that later instalment is not payable by the payer;
the payer must pay the instalment referred to in paragraph (a) on the day that would have been the payday for the later instalment if it had been payable by the payer.