State tax filing

If you really are a "Domiciliary Resident" of VA then you can put any date in the "My Info" section as you will change the form type to resident form 760 in the VA state interview.  First, be sure you are a "Domiciliary Resident". Here is the VA reference.

"Domiciliary Residents: Individuals whose state of legal residence in the technical sense is Virginia are domiciliary residents. Most domiciliary residents actually live in Virginia. Examples of individuals who are domiciliary residents but who do not live in Virginia are shown below:

• An individual who enters the military from Virginia (i.e., claims Virginia as his/her home of record) will remain a domiciliary resident of Virginia, unless appropriate steps are taken to abandon Virginia as the state of domicile.
• A student who attends school in another state, but maintains Virginia as his/her legal state of residence, is a domiciliary resident.
• A resident of Virginia who accepts employment in another country is a domiciliary resident, unless appropriate steps are taken to abandon Virginia as the state of domicile."

These are some examples of steps that can be taken to abandon VA as the state of domicile.  

• As You state that you moved out several years ago; you live and work in VT.   
• Have you established closer ties to VT than VA?  
• Where do you spend the most time?  
• Did you actually spend more than 183 days in VA?  
• Where are you registered to vote?  
• Do you own a property in VT?   
• Where are your vehicle(s) registered?  
• Where is your primary care physician? 

I would surmise VT is your resident state and you do not have a VA filing requirement.  

However, if you truly are a "Domiciliary Resident" it is full-year; you file a VA Form 760; not 760PY.  So when you get to the VA state interview you will be asked to verify you were part-year VA resident.  You will select no and select "Lived in VA all year." Here is the VA Department of Revenue reference (extracted below). You will not be able to subtract any income out of VA source income.  You will have to claim a credit for taxes paid to another state on your resident VA return. 

"If you are a Virginia resident, file your income tax return on Form 760. Some points you should keep in mind:

• A Virginia resident return must include income from all sources.
• No subtractions are allowed for income reported to other states. Income taxes paid to other states are addressed through tax credits."

Finally, in the VT state interview you will also be asked to verify part-year residency.  Again you will answer No and change the residency to full year.  You will be filing as dual resident.