It's interesting that many states, like Virginia, will consider you to be a Virginia resident forever, unless you actually move to and live in another state. Going overseas doesn't count. There are people who have left Virginia, sold their house and vehicle and moved to Mexico, Germany, or another country with no intention to ever return to Virginia. But, according to Virginia law, they are still a Virginia resident for tax purposes, even though they have no connection to Virginia, and they cannot even vote in Virginia.

June 15 to end of December is 195 days more than 183. I have moved to Michigan, Illinois, Wisconsin and Florida. You had to prorate taxes because of being a part year residence. I can’t remember which ones but some asked for utility bill, lease agreement, etc. however switching plates, title and drivers license sealed the deal.