40 CFR § 60.1420
If a semiannual report is required, when must I submit it?
June 9, 2020
(a) For data collected during the first half of a calendar year, submit your semiannual report by August 1 of that year.
(b) For data you collected during the second half of the calendar year, submit your semiannual report by February 1 of the following year.