Time of supply in other situations :
In case it is not possible to determine the time of supply under any of aforesaid provisions, 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 CGST/SGST is paid – section 12(5) of CGST Act.