DayProof: 183 Days Residency

DayProof counts the days you spend in each place and tells you how close that puts you to being a tax resident there. There is no single 183-day rule. That is the whole problem. Maryland's line is "183 days or more." Massachusetts says "more than 183." Sit on exactly 183 and those two disagree about what you are. Portugal only counts a day you slept there, so your flight home is free. Britain decides at midnight, over a tax year that starts on 6 April, and Australia wants more than half the income year, which is 183 days most years and 184 after a leap day. Germany, France, Japan, Mexico and Turkiye have no day count in the law at all, whatever the internet tells you. I read the statutes rather than the summaries, and DayProof carries each rule the way its own revenue department wrote it, with the source and the date I checked it printed underneath. Where a country has no number, it…