Conn. Gen. Stat. § 9-391

(b) Each selection of delegates to a state or district convention shall be made in accordance with the provisions of section 9-390 not earlier than the one-hundred-fortieth day and not later than the one-hundred-thirty-third day preceding the day of the primary for such state or district office. Such selection shall be certified to the clerk of the municipality by either the chairperson or presiding officer or the secretary of the town committee or caucus, as the case may be, not later than four o'clock p.m. on the one-hundred-thirty-second day preceding the day of such primary. Each such certification shall contain the name and street address of each person so selected, the position as delegate, and the name or number of the political subdivision or district, if any, for which each such person is selected. If such a certificate of a party's selection is not received by the clerk of the municipality by such time, such certificate shall be invalid and such party, for the purposes of sections 9-417 and 9-420 , shall be deemed to have neither made nor certified any selection of any person for the position of delegate.

(c) Each endorsement of a candidate to run in a primary for the nomination of candidates for a municipal office to be voted upon at a state election shall be made under the provisions of section 9-390 not earlier than the eighty-fourth day or later than the seventy-seventh day preceding the day of such primary. Each certification to be filed under this subsection shall be received by the Secretary of the State not later than four o'clock p.m. on the fourteenth day after the close of the town committee meeting, caucus or convention, as the case may be. If such a certificate of a party's endorsement is not received by the Secretary of the State by such time, such certificate shall be invalid and such party, for the purposes of sections 9-417 and 9-418 , shall be deemed to have neither made nor certified any endorsement of any candidate for such office. The candidate so endorsed for a municipal office to be voted upon at a state election, other than the office of justice of the peace, shall file with the Secretary of the State a certificate, signed by that candidate, stating that such candidate was so endorsed, the candidate's name as the candidate authorizes it to appear on the ballot, the candidate's full street address and the title and district of the office for which the candidate was endorsed. Such certificate may be filed by a candidate whose name appears upon the last-completed enrollment list of such party within the senatorial district within which the candidate is endorsed to run for nomination in the case of the municipal office of state senator, or the assembly district within which the candidate is endorsed to run for nomination in the case of the municipal office of state representative, or the municipality or political subdivision within which the candidate is to run for nomination for other municipal offices to be voted on at a state election. Such certificate shall be attested by either the chairperson or presiding officer or the secretary of the town committee, caucus or convention which made such endorsement. The endorsement of any candidate for the office of justice of the peace shall be certified to the clerk of the municipality by either the chairperson or presiding officer or the secretary of the town committee, caucus or convention, and shall contain the name and street address of each candidate so endorsed and the title of the office for which each such candidate is endorsed. Such certification shall be made on a form prescribed by the Secretary of the State or on such other form as may comply with the provisions of this subsection.

See Sec. 9-406a re penalty for fraudulent certification.