For a supply of services, neither clause (a) nor clause (b) of section 13(2) of the CGST Act, 2017 applies. Which date does clause (c) use as the time of supply?

Section 13(2)(c) of the CGST Act makes the time of supply the date on which the recipient shows receipt of services in its books of account, where clauses (a) and (b) do not apply. The invoice and payment dates are the tests under clauses (a) and (b), and completion of the service is relevant only to whether the invoice was issued in time.