Section 13(2)(b) in The Central Goods and Services Tax Act, 2017
(b)the date of provision of service, if the invoice is not issued within the period prescribed under [OMIT] [Omitted 'sub-section (2) of' by Act No. 31 of 2018, dated 29.8.2018.] section 31 or the date of receipt of payment, whichever is earlier; or