As an international F-1 student who lived in WA for over 5 years, I moved to CA on 9/20/2021 and stayed till now. What was my State of residence (on December 31, 2021)?

I lived in WA for over 5 years so I am considered WA resident and Resident Alien for tax purpose. However, I moved to CA for study on 9/20/2021 and stayed till now. What was my State of residence (on December 31, 2021)?

If I continue stay in CA, when will I become a CA resident? For example, I continue to stay and work in CA after graduating in 2022.