Effective date insertion clarifies when a GST notification takes effect by amending prior text under statutory authority. The notification amends the earlier instrument by inserting the words 'on and with effect from the 13th October, 2017' after 'following amendment,' effected under the powers conferred by sub-section (1) of section 11 of the Punjab Goods and Services Tax Act, 2017, thereby clarifying the temporal operation of the prior notification.