For purposes of this subtitle, the taxable year of an S corporation shall be a permitted year.
For purposes of this section, the term “permitted year” means a taxable year which—
(1) is a year ending December 31, or
(2) is any other accounting period for which the corporation establishes a business purpose to the satisfaction of the Secretary.
(Added Pub. L. 97–354, § 2, Oct. 19, 1982, 96 Stat. 1685; amended Pub. L. 98–369, div. A, title VII, § 721(m), (q), July 18, 1984, 98 Stat. 969, 970; Pub. L. 99–514, title VIII, § 806(b), Oct. 22, 1986, 100 Stat. 2363.)