Conn. Gen. Stat. § 12-142
The legislative body of each municipality, upon approving any budget calling for the laying of a tax on property, shall determine whether such tax shall be due and payable in a single installment or in two semiannual installments or in four quarterly installments and shall, unless otherwise provided by law, designate the date or dates on which such installment or installments shall be due and payable, subject to the provisions of section 7-383, in any municipality in compliance with requirements concerning the uniform fiscal year under chapter 110; provided the last installment of any such tax shall be due and payable not later than forty-five days before the end of the fiscal year in which the first installment thereof is due and payable, and provided any special tax shall be due and payable in a single installment. In case of failure of the legislative body to determine when such tax shall be due and payable or whenever the date on which such tax shall be due and payable has been determined, however, (1) the preparation and mailing of rate bills for such tax is delayed until after the date such tax is due or (2) such tax is not applicable to certain property until after the date such tax is due, such tax shall be due and payable, with respect to all property or property which becomes subject to tax after the date such tax is due, whichever is applicable, not later than thirty days following the date on which rate bills for such tax are mailed or handed to persons liable therefor. Except as otherwise provided by law, the several installments of a tax due in two or four installments shall be equal, but any taxpayer may pay two or more of such installments when the first is due.
Conn. Gen. Stat. § 12-142
(1949 Rev., S. 1824; P.A. 83-579, S. 2, 3.)
This date determines beginning of year during which collector may continue by certificate the lien of taxes on real property. 101 C. 389.
See Sec. 7-383 re due date of tax levy. See 12-63 a(d) re payment of taxes on mobile homes.