Section 13(5) in The Punjab Goods and Services Tax Act, 2017
(5)Where it is not possible to determine the time of supply under the provisions of sub-section (2) or sub-section (3) or sub-section (4), the time of supply shall-(a)in a case where a periodical return has to be filed, be the date on which such return is to be filed; or(b)in any other case, be the date on which the tax is paid.
