Quarterly filing of FORM GSTR 1 required for eligible small taxpayers, with prescribed quarterly deadlines and subsequent time limit notifications. Requires registered persons whose aggregate turnover falls within a notified threshold to furnish details of outward supplies in FORM GSTR 1 on a quarterly basis, with specified deadlines for the quarters July-September 2017, October-December 2017 and January-March 2018. Issued under section 148 of the CGST Act, the notification states that any special procedure or extension of time limits under section 38(2) and section 39(1) for July 2017-March 2018 will be notified subsequently in the Official Gazette.