The mayor or other chief executive officer of such municipality shall immediately upon receipt of such certificate from the judge of probate, by proclamation, submit the question of the adoption of the council-manager form of government for such municipality under this article, at a special election to be held at a time specified in such proclamation, not less than 40 days nor more than 90 days after the receipt of said certificate from said judge of probate, unless a general election is to be held within 120 days after receipt of such certificate in which event the special election herein provided for may be held at the same time as such general election. Should the election not be called by proclamation within 10 days after receipt of the certificate, the judge of probate shall call such election by order at a time specified therein but not less than 40 days and not more than 90 days after the receipt by said mayor, or other executive officer of the said certificate of the judge of probate, unless a general election is to be held within 120 days after receipt of such certificate, in which event the special election herein provided for shall be held at the same time as such general election.