Special township meetings shall be held when the township board (or at least 15 voters of the township) file in the office of the township clerk a written statement that a special meeting is necessary for the interests of the township. The statement also shall set forth the objects of the meeting, which must be relevant to powers granted to electors under this Code. The special township meeting shall be held no less than 14 nor more than 45 days after the written request is filed in the office of the township clerk. Special township meetings may not begin before 6 p.m.