Due date extension for GSTR-1 filings for specified high-turnover registrants; revised monthly deadline to be notified. Extension of the due date is prescribed for furnishing details of outward supplies in FORM GSTR-1 by the class of registered persons whose aggregate turnover exceeds the specified threshold, for each monthly tax period from October 2020 to March 2021, to be furnished by the eleventh day of the month succeeding the relevant month; the time limit for furnishing details or return under the complementary provision for the same months will be notified subsequently, and the notification is deemed to have come into force on 15 October 2020.