If you are not domiciled in Maine but maintain a permanent place of abode there for the entire tax year, spending more than 183 days in Maine generally makes you a Maine resident for income-tax purposes. Any part of a day counts as a full day. This tracker monitors days only and does not determine domicile or whether you maintain a permanent place of abode. Members of the U.S. Armed Forces are excluded from this statutory-residency provision.
https://www.mainelegislature.org/legis/statutes/36/title36sec5102.html