From page 5 of the 2021 CA FTB Publication 1031:
"You will be presumed to be a California resident for any taxable year in which you spend more than nine months in this state."
https://www.ftb.ca.gov/forms/2021/2021-1031-publication.pdf
So if you live in California for 10 months in 2023, you'll have to file your California tax return as a resident, which means that all your 2023 income will be subject to CA income tax.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
