Conn. Gen. Stat. § 7-383

The first installment of the general property tax levy of each complying municipality for its fiscal year beginning the first day of July, or the whole of such levy if such levy is not payable in more than one installment, shall become due on the first day of such fiscal year, provided whenever (1) the preparation and mailing of rate bills for such tax levy is delayed until after the date such tax is due or (2) such tax levy 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. Any municipality not yet complying may provide by majority vote of its legislative body that the first installment on such levy shall become due on the first day of January and the second installment on such levy shall become due on the first day of July, until such municipality complies.