The short answer
Usually yes. Under the Schengen 90/180 rule and most tax day-counts (including the US substantial presence test and Canada's 183-day sojourner rule), any day you set foot in the country counts as a full day, so both your arrival and departure days count, no matter the time of day. The main exception is the UK Statutory Residence Test, which generally counts a day only if you are in the UK at midnight, so your departure day usually does not count.
For Schengen, the rule is explicit: the day of entry is the first day of stay and the day of exit is the last day of stay, and both are counted in full. Landing near midnight and leaving early the next morning still uses up two days. Since the EU's Entry/Exit System (EES) began rolling out on 12 October 2025, these crossings are increasingly logged biometrically rather than by passport stamp, so the count is recorded automatically. (ETIAS, the separate travel authorisation, is expected later, around late 2026 — timing may shift.)
US federal tax uses the same "any part of a day" logic: for the substantial presence test you are treated as present on any day you are physically in the US at any time, so arrival and departure days both count. Narrow exceptions exist — for example, less than 24 hours in transit between two places outside the US, regular commuters from Canada or Mexico, and certain exempt visa holders. Canada applies the same principle for its 183-day sojourner rule: the CRA treats any part of a day in Canada as a full day. US state statutory-residency tests (such as New York, New Jersey, Connecticut, Massachusetts and Pennsylvania) also generally count any part of a day, with their own specific rules; New York City applies its own version, and California has no fixed day count at all (more than about nine months creates only a rebuttable presumption).
The notable outlier is the UK Statutory Residence Test, which uses a midnight test: a day normally counts only if you are in the UK at the end of that day. So your arrival day usually counts and your departure day usually does not — though a transit exception, the "deeming rule" for frequent visitors with UK ties, and exceptional-circumstances rules can change this. Day-counting is one of the easiest things to get wrong, so where the result is close to a threshold, confirm the exact method with the relevant tax or border authority. This is general information, not legal or tax advice, and exceptions always apply.
Stop counting by hand.
Countly tracks your days across borders automatically and privately — and warns you before any limit.