D.C. Mun. Regs. tit. 10, r. 10-C3206
In computing any period of time specified in this chapter, calendar days shall be counted unless otherwise indicated.
In computing any period of time specified in this chapter, the day of the act, event, or default after which the designated period of time begins to run is not included. The last day of the period so computed is included unless the period ends on a Saturday, Sunday, or holiday, in which case the period runs until the end of the next business day.
The one hundred twenty (120) day period provided by the Act during which the Mayor must act on an application, shall be computed from the date the Review Board receives the referral of a complete application from DCRA, or for applications subject to review under the Old Georgetown Act or the Shipstead-Luce Act, from the date the CFA receives the referral.
The provision of a forty-five (45) day notice to Advisory Neighborhood Commissions is intended to address the statutory requirement for a notice period of thirty (30) working days. If there is a discrepancy, the calculation by working days shall control.
Except as otherwise provided by law, whenever an act is required or allowed to be done at or within a specified time, the time fixed or the period of time prescribed may for good cause be extended or shortened by the Mayor's Agent, SHPO or Board, as the case may be.
Except as otherwise provided by law, failure to take action within a time period specified in these rules shall not invalidate an otherwise proper action pursuant to the rules.
D.C. Mun. Regs. tit. 10, r. 10-C3206