42 U.S.C. § 909: Delivery of benefit checks

If the day regularly designated for the delivery of benefit checks under subchapter II, VIII, or XVI falls on a Saturday, Sunday, or legal public holiday (as defined in section 6103 of title 5 ) in any month, the benefit checks which would otherwise be delivered on such day shall be mailed for delivery on the first day preceding such day which is not a Saturday, Sunday, or legal public holiday (as so defined), without regard to whether the delivery of such checks would as a result have to be made before the end of the month for which such checks are issued. If more than the correct amount of payment under subchapter II, VIII, or XVI is made to any individual as a result of the receipt of a benefit check pursuant to subsection (a) before the end of the month for which such check is issued, no action shall be taken (under section 404 or 1383(b) of this title or otherwise) to recover such payment or the incorrect portion thereof. For purposes of computing the “OASDI trust fund ratio” under section 401( l ) of this title, the “OASDI fund ratio” under section 415(i) of this title , and the “balance ratio” under section 910(b) of this title , benefit checks delivered before the end of the month for which they are issued by reason of subsection (a) of this section shall be deemed to have been delivered on the regularly designated delivery date.