For other reading this: be advised that New York, Pennsylvania, Nebraska, Delaware and Arkansas and Massachusetts (to a degree) have the same rule.
If you work outside the state as a job requirement, you are only subject to New York State income tax on the days you physically work in New York. But if you work outside New York for your own convenience, you are subject to New York State income tax on all your income. Pennsylvania, Nebraska, Delaware and Arkansas have the same rule. Massachusetts is a newcomer to the list, as it adopted a temporary measure to continue taxing the wages of workers residing in New Hampshire amid the pandemic.
