For the sake of simplicity, let's suppose that a person's total yearly income is $100,000, all as W2 wages from the same employer. That person lived in one state from January 1 - June 30, and then moved to California on July 1, and lived there for the remainder of the year.
A quick reading of the official California tax site suggests that the CA income tax would be based on $50,000 (i.e. the amount of yearly income the person earned while a resident of the state, which was for exactly 1/2 of the year).
But then I found this site, which suggests something very different (that the amount of tax is based on the $100,000 yearly income, but simply divided by 2 due to the half-year residency).
So which one is correct? Do the progressive brackets "reset" when one takes up residency?