Here's a link to Virginia's actual law regarding taxable income of non-residents:
https://law.lis.virginia.gov/admincode/title23/agency10/chapter110/section180/
My personal (and unofficial) interpretation of the law would be that, since your benefits such as sick pay, vacation pay, holiday pay, etc., are general benefits of your employment and not specifically "earned in Virginia", those days would not be included when calculating your VA-taxable income. I would only count the days you actually worked in Virginia.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
