The tax imposed by this subchapter shall be due and payable by the executor at the time the Vermont estate tax return is required to be filed under section 7446 of this title, without extension. (Added 1969, No. 269 (Adj. Sess.), § 1, eff. date, see note under § 7401 of this title; amended 1995, No. 29, § 12, eff. April 14, 1995; 2003, No. 70 (Adj. Sess.), § 53, eff. March 1, 2004.)