(23) Taxable year The term “taxable year” means the calendar year, or the fiscal year ending during such calendar year, upon the basis of which the taxable income is computed under subtitle A. “Taxable year” means, in the case of a return made for a fractional part of a year under the provisions of subtitle A or under regulations prescribed by the Secretary, the period for which such return is made.
26 USC § 7701(a)(23)
None identified. Default scope is assumed to be the entire title.