Section 2.306 - Computation of time(a) In computing any period of time, 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 it is a Saturday or Sunday, a Federal legal holiday at the place where the action or event is to occur, or a day upon which, because of an emergency closure of the Federal government in Washington, DC, NRC Headquarters does not open for business, in which event the period runs until the end of the next day that is not a Saturday, Sunday, Federal legal holiday, or emergency closure.(b) Whenever a participant has the right or is required to do some act within a prescribed period after the service of a notice or other document upon him or her, no additional time is added to the prescribed period except in the following circumstances: (1) If a notice or document is served upon a participant, by first-class mail only, three (3) calendar days will be added to the prescribed period for all the participants in the proceeding.(2) If a notice or document is served upon a participant, by express mail or other expedited service only, two (2) calendar days will be added to the prescribed period for all the participants in the proceeding.(3) If a document is to be served by multiple service methods, such as partially electronic and entirely on portable storage media, the additional number of days is computed according to the service method used to deliver the entire document, excluding courtesy copies, to all of the other participants in the proceeding. The presiding officer may determine the calculation of additional days when a participant is not entitled to receive an entire filing served by multiple methods.(4) In mixed service proceedings when all participants are not using the same filing and service method, the number of days for service will be determined by the presiding officer based on considerations of fairness and efficiency.(c) To be considered timely, a document must be served:(1) By 5 p.m. Eastern Time for a document served in person or by expedited service; and(2) By 11:59 p.m. Eastern Time for a document served by the E-Filing system. 72 FR 49151 , Aug. 28, 2007