Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 48, § 55

A town which has established a fire department may vote to fix the term of office for the members of such department at one year from a designated day, and may at the same time determine the then current term of office of members of fire departments; but no term shall be made shorter than six or longer than eighteen months, and the incumbents shall hold office until others are appointed in their stead. In such cases all provisions of this chapter referring to the month of May shall be construed to refer to the first month of the year thus designated.