Date of entry into United States: 2013年9月
Exempt individual: 2013年9月 through 2016年9月
(student on J-1 visa is “Exempt Individual” for 3 calendar years, 2013
through 2016)
Nonexempt individual starting from 09/2016 ------
Begin counting 183 days at this date: 09/2016
I am not exactly sure it was three years or two years for J1. Either way you
are nonresident in 2015