Here is my situation:
-I am a married graduate student.
-My husband and I own a house in New York State (NYS).
-My husband and I file jointly.
-My advisor/grant paid for the sublease of an apartment in New York City (NYC) for me to do research for 7 weeks this year during which time my husband continued to maintain our residence outside of NYC.
-My pay was still via the university outside of New York City.

The question I'm trying to figure out is, do I have to file taxes as a part time NYC resident?
- If I do have to file, can I only include my income since my husband was not a resident of NYC.
- How do you fill out the IT‑360.1 to reflect that this was a temporary change in residency?

Since your stay in NYC was temporary and you continued to maintain a residency outside of NYC I believe you do not need to pay NYC resident tax on your income during those 7 weeks.