Conn. Gen. Stat. § 52-82: Withdrawal when court not in session or before return day.

The plaintiff may withdraw a civil action when the Superior Court is not in session or at any time before the return day, by filing in the clerk's office a written notice of the withdrawal, signed by himself or his attorney, specifying the action withdrawn and the time of withdrawal. The clerk shall enter the action on the docket of the court, at or before its next return day, with a note of the withdrawal and of its date.