5. Change in the rate of tax.—

 If there is a change in the rate of tax--

            (a) a taxable supply made by a registered person shall be charged to tax at such rate as

is in force at the time of supply;

            (b) imported goods shall be charged to tax at such rate as is in force,--

                     (i)   in case the goods are entered for home consumption, on the date on which a goods

declaration is presented under section 79 of the Customs Act, 1969 (IV of 1969);

                     (ii)   in case the goods are cleared from warehouse, on the date on which a goods declaration for

clearance of such goods is presented under section 104 of the Customs Act, 1969 (IV

of 1969):

                                Provided that where a goods declaration is presented in advance of the arrival of the

conveyance by which the goods are imported, the tax shall be charged as is in

force on the date on which the manifest of the conveyance is delivered:

                        Provided further that if the tax is not paid within seven days of the presenting of the

goods declaration under section 104 of the Customs Act, the tax shall be charged at the

rate as is in force on the date on which tax is actually paid.