The registrars shall make changes and corrections in the list of enrolled electors at any time. On the fourteenth day before each primary, the registrars of voters in each town shall hold a mandatory enrollment session for the purpose of making an enrollment of the electors who are entitled to vote in primaries. All enrollment sessions of the registrars of voters shall be held in a public place maintained by the municipality at such hours between twelve o’clock noon and nine o’clock p.m. as said registrars prescribe, provided each such session shall be held for not less than two consecutive hours and provided, in any municipality divided into voting districts in which an enrollment session is held in each such district, the hours of such session in each of the districts shall be uniform. This section shall apply in each municipality, the provisions of any special act to the contrary notwithstanding.