The Fair Labor Standards Act (FLSA) does not require payment for time not worked, such as vacations or holidays (federal or otherwise). These benefits are generally a matter of agreement between an employer and an employee (or the employee's representative).
On a government contract to which the labor standards of the McNamara O'Hara Service Contract Act (SCA) apply, holiday and/or vacation fringe benefit requirements are stated in the SCA wage determinations in contracts that exceed $2,500.
On a government contract to which the labor standards of the Davis-Bacon and Related Acts apply, holiday pay and/or vacation pay is required for specific classifications of workers only if the Davis-Bacon wage determination in the covered contract specifies such requirements for workers employed in those classifications.
Webpages on this Topic
"How are Vacation Pay, Sick Pay, Holiday Pay Computed?"
Information from the elaws FLSA Advisor.
Coverage Under the Fair Labor Standards Act (FLSA)
Fact sheet on who is covered by the FLSA.
Regulations on this Topic
29 CFR Part 4.174 - Regulations on Meeting Requirements for Holiday Fringe Benefits for Federal Contracts