Computation of time.
CFR · 2024-01-01 · US · Title 7
A period of time begins with the day following the act or event and includes the last day of the period, unless it is a Saturday, Sunday, or legal holiday observed in the District of Columbia, in which case it shall be the following workday. When the period of time prescribed or allowed is less than 7 days, intermediate Saturdays, Sundays, and legal holidays shall be excluded from the computation.
official document · source cfr-2024 · id 7:§ 15.63