"Does New Jersey sourced income mean the income I received for the days I physically worked remotely in NJ (rather than in Florida)? "
Answer: Yes.
"If so, am I just dividing my gross income by the workdays (not calendar days) I am in New Jersey?"
Answer: Follow the allocation instructions in Part II (page 29) of the 2023 NJ-1040NR instructions.
https://www.nj.gov/treasury/taxation/pdf/current/1040nri.pdf
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
