In computing any period of time described in these rules, "days" refer to calendar days, unless otherwise specified in these rules. The first day from which the period begins to run is not counted, and when the last day of the period is Saturday, Sunday, or a Federal holiday, the period extends to the next day that is not a Saturday, Sunday, or a Federal holiday. Documents shall be deemed "filed" on the date and time received by the Board if received before 5:30 p.m. local time in Washington, DC, or the next business day if received after 5:30 p.m.
4 C.F.R. §22.28