27 CFR § 44.148
Opening
April 24, 2020
An opening report, covering the period from the date of the opening inventory, or inventory made in connection with a superseding bond, to the end of the month, shall be made on or before the 20th day following the end of the month in which the business was commenced.
(72 Stat. 1422; 26 U.S.C. 5722)