The judgment of the Court was delivered by

DESAI, J. - The assessee was a dealer registered under the Bombay Sales Tax Act, 1959 (hereinafter referred to as "the Bombay Act"), and the Central Sales Tax Act, 1956 (hereinafter referred to as "the Central Act"). It carried on the business of oil-seeds, jira, variali, etc., at Patan in Mehsana District. By an order made on 4th January, 1967, in exercise of the power conferred by section 32(1) of the Bombay Act read with rules 24 and 29 of the Bombay Sales Tax Rules, 1959 (hereinafter referred to as "the Bombay Rules"), the competent authority permitted the assessee to furnish, with effect from the date of the said order, returns in form 18 for the periods specified in column 1 of the schedule forming part of the order (in lieu of the quarterly returns) on or before the dates specified in column 2 of the said schedule on the condition that the assessee should pay the amounts specified in column 3 of the said schedule on or before the date specified in column 4 thereof. The said schedule, which has a bearing on the decision of this case, is reproduced hereunder :

SCHEDULE

------------------------------------------------------------------------ Period of return Last date of Amount to be paid Last date for submission of payment towards returns tax 1 2 3 4 ------------------------------------------------------------------------

1st April, to 30th November. (a) Rs. 451.00 or 31st August. Asho Vad Amas. the tax due according to the dealer's account from 1st April, to Asho Vad 30.

(b) Tax due 30th November. according to the dealer's account for the period from 1st April, to Ashvin Vad 30, less the tax already paid under item (a). Kartak Sud 1 30th April. (c) Rs. 451.00 or 28th or 29th to 31st March the tax due February. according to the dealer's accounts for the period from Kartak Sud 1 to Posh Vad Amas.

(d) Tax due according to the dealer's account for the period from Kartak Sud 1 to 31st March, less the tax already paid under item (c). ------------------------------------------------------------------------

The Bombay Act was in force up to 5th May, 1970. On and with effect from 6th May, 1970, the Gujarat Sales Tax Act, 1969 (hereinafter referred to as "the Gujarat Act"), came into force. Section 88 of the Gujarat Act repealed the Bombay Act.

On 4th May, 1970, the State Government amended the Bombay Rules by inserting rule 23A in the said Rules in exercise of the powers c