Section 23.10 - General Provisions(1) Effect of Presumptions. All presumptions explicitly described in these regulations are rebuttable. Whether a presumption has been rebutted is a determination made by the Attorney General in his or her discretion.(2) Time Computation. In computing any period of time prescribed by these regulations, the day of the act or event from which the designated period of time begins to run shall not be included. The last day of the period so computed shall be included, 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. When the period of time prescribed or allowed is less than 7 days, intermediate Saturdays, Sundays, and legal holidays shall be excluded in the computation. "Legal holidays" are those days specified in M.G.L. c. 4, s. 7 and any other day appointed as a holiday by the President or the Congress of the United States or designated by the laws of the Commonwealth.