Me. Rev. Stat. tit. 36, § 760

Municipal assessors, or municipal officers in the case of primary assessing areas, shall specify in the tax collector's warrant the date on or before which the tax collector must perfect collections. Such date may not be less than one year from the date of the commitment of taxes. In the event that a time is not specified in the tax collector's warrant, tax collectors shall perfect their collections within 2 years after the date of the commitment of taxes.