What is correct date for change in state residency and state taxes/credits?

[yz12]

Trying to figure out when my residency changed and sorting out state taxes and credits.

Change in residency

• I lived in PA and started a new job in NY in May
• I moved to NJ in Aug
• For my part year tax returns in PA and NJ, when would be the date where residency changed?

New company paid NY state tax from start (W-2 only shows NY state taxes paid) 

• Should I calculate and include in the PA return the prorated NY income and NY taxes paid (for credit)?

W-2 shows NJ income (box 16) that is less than NY income (box 16) and no NJ taxes withheld

• For the NJ return, should I use the NJ number (box 16) or change to the higher NY number (box 16)?

Thanks in advance for your help.

[Hal_Al]

Q. For my part year tax returns in PA and NJ, when would be the date where residency changed?

A. August

Q.  Should I calculate and include in the PA return the prorated NY income and NY taxes paid (for credit)?

A.  Yes. Part of it (May - Aug) will be prorated to PA and the rest to NJ.

Q. For the NJ return, should I use the NJ number (box 16) or change to the higher NY number (box 16)?

A. Use the NJ number, the difference is allocated to PA. 

[TomD8]

To be precise, you became a resident of NJ on the day you began living in your new home in NJ.