Extension of deadline under GST notification extends applicability and declares retrospective commencement to the original effective date. The notification substitutes the earlier deadline of 30th day of June, 2023 with the 31st day of August, 2023, extending the temporal scope of the referenced provision; the amendment is issued under state GST powers and is declared to be deemed to have come into force with effect from the 30th day of June, 2023.