25 CFR § 2.15
Computation of time
February 24, 2021
In computing any period of time prescribed or allowed in this part, calendar days shall be used. Computation shall not include the day on which a decision being appealed was made, service or notice was received, a document was filed, or other event occurred causing time to begin to run. Computation shall include the last day of the period, unless it is a Saturday, a Sunday, or a legal holiday, in which event the period runs until the end of the next day which is not a Saturday, a Sunday, or a legal holiday.