majority U.S. shareholder year
(3) Majority U.S. shareholder year (A) In general For purposes of this subsection, the term “majority U.S. shareholder year” means the taxable year (if any) which, on each testing day, constituted the taxable year of— (i) each United States shareholder described in subsection (b)(2)(A), and (ii) each United States shareholder not described in clause (i) whose stock was treated as owned under subsection (b)(2)(B) by any shareholder described in such clause. (B) Testing day The testing days shall be— (i) the first day of the corporation’s taxable year (determined without regard to this section), or (ii) the days during such representative period as the Secretary may prescribe.