2. In these Regulations—

"advance payment" meas the advance payment referred to in section 19 (6) of the Principal Act;

"due date" means the due date referred to in section 19 (6) of the Principal Act;

"November liability" means—

(a) the amount of tax which would be payable in accordance with section 19 (3) of the Principal Act, or

(b) nil, where an amount of tax would be repayable in accordance with section 20 (1) of the Principal Act,

if the November period were to be treated as a taxable period;

"November period" means the month of November immediately preceding a due date;

"the Principal Act" means the Value-added Tax Act, 1972.