21 USC 1053 - Inspection and administration costs

(a) Overtime and holiday work costs; availability of funds 
The cost of inspection rendered under the requirements of this chapter, and other costs of administration of this chapter, shall be borne by the United States, except that the cost of overtime and holiday work performed in official plants subject to the provisions of this chapter at such rates as the Secretary may determine shall be borne by such official plants. Sums received by the Secretary from official plants under this section shall be available without fiscal year limitation to carry out the purposes of this chapter.
(b) “Holiday” defined 
The term holiday for the purposes of assessment or reimbursement of the cost of inspection performed under this chapter, the Wholesome Poultry Products Act [21 U.S.C. 467a et seq.] and the Wholesome Meat Act [21 U.S.C. 601 et seq.] shall mean the legal public holidays specified by the Congress in section 6103 (a) of title 5.