Mass. Gen. Laws ch. 53, § 92

Notices of caucuses in said cities or towns shall state the place where and the day and hour when nomination papers shall be issued; the place where and the earliest day and hour when such nomination papers may be filed, which time shall be not less than twenty-four week day hours succeeding three o'clock of the day fixed for issuing such papers; the place where and the day and hour prior to which such nomination papers shall be filed; and the day on which the several caucuses will be held, and shall be issued not less than eighteen days prior thereto.