“Owner” means the same as that term is defined in § 58.1-390.1. “Pass-through entity” means the same as that term is defined in § 58.1-390.1. “Taxable year” when used in regard to pass-through entities means the taxable year of the pass-through entity for federal income tax purposes. If a pass-through entity does not have a taxable year for federal tax purposes, its tax year for purposes of this article shall be the calendar year.