Drawback effective date rules govern retrospective application, notification requirements, and the applicable rate for exported goods. The Central Government may specify the period for which any amount or rate of drawback determined or revised under the rules remains in force. Where drawback is allowed with retrospective effect, the effective date must be fixed by notification in the Official Gazette and cannot be earlier than the date of changes in the rates of duty on inputs used in the export goods. The applicable amount or rate of drawback for goods exported under these rules is governed by section 16, or section 83(2), of the Customs Act, 1962.