Taxable year
(A) In general For purposes of this title, an alien individual who has not established a taxable year for any prior period shall be treated as having a taxable year which is the calendar year.
(B) Fiscal year taxpayer If— (i) an individual is treated under paragraph (1) as a resident of the United States for any calendar year, and (ii) after the application of subparagraph (A), such individual has a taxable year other than a calendar year, he shall be treated as a resident of the United States with respect to any portion of a taxable year which is within such calendar year.