How to Count Your Days: Schengen 90/180, the UK's 180 Days and the US 183-Day Test

In short: If you live, work or travel across countries, three day-counting rules come up again and again: the Schengen area's 90 days in any 180, the UK's 180 days of absence in any 12 months for settlement, and the US substantial presence test's 183 weighted days. Each counts days differently, and the differences are where people get caught out. This playbook works through each rule as its own authority publishes it, with examples, and shows how to keep a record of your days that an adviser can check. Nothing here is legal, tax or immigration advice. The counts are arithmetic, and the authority or your adviser decides what they mean for you.

Key takeaways

• Schengen counts both your entry and your exit day as whole days, over a window that moves with every day of your stay.
• The UK counts only whole days absent. The day you leave and the day you return are not absences.
• The US counts any part of a day as a day present, then weights the two previous years at a third and a sixth.
• A count is only as good as the record behind it. Days you have no record of should be listed, never guessed.
• For Schengen, the EU's own Entry/Exit System record decides when your count and theirs differ.

The Schengen 90/180 rule, day by day

What the rule says

Under the Schengen Borders Code (Regulation (EU) 2016/399, Article 6), a visitor may stay 90 days in any 180-day period, "which entails considering the 180-day period preceding each day of stay". The European Commission's guidance puts it plainly: count back 180 days from each day of your stay and make sure the total does not exceed 90.

How to count it

1. Every day with any part spent inside the Schengen area counts as a whole day. The day you enter is the first day of your stay and the day you leave is the last, so a same-day visit counts as one day.
2. For any day, look back 180 days, that day included, and count the days you were inside. That window is the day itself and the 179 days before it.
3. That number must be 90 or less on every day of your stay, not just on the day you arrive.
4. The days you have left today are 90 minus the days used in the current window.

A worked example from the Swiss migration authority: enter on 1 January, leave on 15 January, and you have used 15 days, because both the entry and the exit day count.

Why "90 days on, 90 days off" is wrong

The window moves every day, so old days drop out one at a time, and your allowance comes back one day at a time, not all at once. Someone who spent 90 days inside, left, and returned 90 days later has a full 90 days again. But someone who did three 30-day trips with short gaps can run out halfway through the third. The only safe way is to count the window for each day of a planned stay.

Who and where it covers

• Who. The rule is for short stays by people who are not EU, EEA or Swiss citizens. UK citizens have been counted under it since Brexit. Days covered by a Schengen residence permit or long-stay visa are not counted in that state.
• Where. The Commission lists 29 countries: 25 EU member states and Iceland, Liechtenstein, Norway and Switzerland. Cyprus and Ireland are not in the Schengen area. Some territories of member states are outside it, among them France's overseas regions and Greenland, while the Canary Islands, Madeira, the Azores and the Balearics are inside.
• Exceptions. Brazilian passport holders fall under an older definition in a bilateral agreement (3 months within 6 months of first entry). A visa granting fewer than 90 days sets its own limit.

The EU's own record now counts too

Since 10 April 2026, the EU's Entry/Exit System (EES) records each crossing at the external border, and the EU offers an online check of how long you can stay. That record is what the border uses. If your own count and the EU's record differ, the EU's record decides, and your own record of your days is the evidence for asking for a correction. Use the European Commission's short-stay calculator to plan, and the EES check to see the EU's own record.

The UK's 180 days of absence for continuous residence

What the rule says

For settlement, the UK's Immigration Rules (Appendix Continuous Residence, CR 3.1) say you "must not have been outside the UK for more than 180 days in any 12-month period". For permission granted on or after 11 January 2018, the Home Office's caseworker guidance considers absences "on a rolling basis over any 12-month period".

How to count it

1. Count whole days only. The guidance: "Part day absences, less than 24 hours are not counted." An absence's whole days are the days strictly between the day you left and the day you returned.
2. Leave on 1 June and return on 10 June, and you were absent for 8 days (2 to 9 June). A day trip, or a one-night trip, is 0.
3. Add up the absences in every 12-month window, not just in each calendar year. Under 180 in each calendar year can still be over 180 in a rolling 12 months.
4. 180 is allowed; 181 is not.

The application forms ask you to list absences once they reach 150 days in any 12 months, a useful early-warning line.

What the count does not cover

Some absences are not counted, for example because of a crisis, travel disruption or compelling circumstances (CR 3.4). Older permissions follow different rules: grants before 11 January 2018 use consecutive 12-month periods, and some Long Residence absences before 11 April 2024 have their own limits. And this rule is not the UK's tax residence test, which counts a day by where you are at midnight.

The US substantial presence test: 183 weighted days

What the rule says

The IRS's substantial presence test (IRC §7701(b)(3)) is met if you were physically present in the United States on at least 31 days in the current year, and 183 days over three years, counting:

• all the days in the current year,
• one third of the days in the year before, and
• one sixth of the days in the year before that.

You are treated as present on any day you are physically in the US at any time during the day.

How to count it

Year	Days present	Weight	Counted
Current year	120	All	120
Last year	120	⅓	40
The year before	120	⅙	20
Total			180, which does not meet the test

That is the IRS's own example. Keep the fractions: a four-month snowbird with 121 days a year reaches 181½, and exactly 183 meets the test while a sixth less does not. Fewer than 31 days in the current year never meets it, whatever the total.

Days that don't count

The IRS lists days that are excluded: regular commuters from Canada or Mexico, under 24 hours in transit between two places outside the US, foreign-vessel crew, a medical condition that arose in the US, and days as an "exempt individual" (for example on certain A, G, F, J, M or Q visas). Excluding them is a filing matter (Form 8843), and a closer connection to another country is a separate exception. Green-card holders are counted under a different test altogether. US territories such as Puerto Rico and Guam have their own rules.

How to keep a record an adviser can check

A count is only as good as the days behind it. The common failures are gaps (weeks with no record), guessed dates, and a spreadsheet nobody can audit.

1. Rebuild the past from evidence you already have. Photos carry a date and a place, and a phone's location history or a Google Maps Timeline export carries more.
2. Record the present as it happens: the country you are in each day, confirmed when you cross a border.
3. Never fill a gap by guessing. List every day with nothing recorded, and show the worst case: what the count would be if each of those days had been spent inside.
4. Keep each rule's count beside the rule's own words, its source and the date you read it. Rules change, and so does guidance.
5. Hand your adviser the evidence, not just the total: your days by place and year, every unrecorded day, and the day-by-day table.

Our residency day tracker for iPhone

We built an iPhone app that does all of the above, and it is coming to the App Store. It records the days you spend in each place, from your photos' dates and places (read on the phone, never uploaded), from your location as you travel if you allow it, or from a CSV or Google Maps Timeline import. It counts each rule as published:

• Schengen 90/180: the days used in the last 180, the latest exit date for the trip you're on, and the date a full 90-day stay opens again.
• UK continuous residence: whole days absent in any 12 months, against 180.
• US substantial presence: the weighted three-year total, with its fractions shown in full.
• Limits you set yourself, for any place and any window.

Every rule screen quotes the rule, links its source and says when it was read. Warnings come before a limit, in days. You can plan a trip and see how it counts before you book. The export for your adviser is a PDF with each rule's count beside its quoted text, your days by place and year, every day with nothing recorded and the full day-by-day table, with a checksum of the CSV it describes.

It keeps everything on your iPhone and in your own iCloud, with no account, no server, no analytics and no third-party code. It is free to download, with a free week and then $49.99 a year; the CSV of your days stays free, always. It counts; it never advises, and it never decides your status. The authority or your adviser does.

Frequently asked questions

How do I count the Schengen 90/180 days?

For each day of your stay, look back 180 days, that day included, and count every day you spent inside the Schengen area, with your entry and exit days counted as whole days. That number may not exceed 90 on any day.

Do the entry and exit days count in Schengen?

Yes. The date of entry is the first day of the stay and the date of exit the last, so both count, and a same-day visit counts as one day.

Does the Schengen count reset after 180 days?

No. The window moves daily, so days drop out of it one at a time. Your allowance returns gradually, not in one reset.

How are UK absences counted for settlement?

As whole days outside the UK: the days strictly between the day you left and the day you returned. Over any rolling 12 months, the total may not exceed 180.

How is the US 183-day rule calculated?

All your days in the US this year, plus a third of last year's, plus a sixth of the year before's. If the total reaches 183 and you were present at least 31 days this year, the test is met. Any part of a day counts as a day.

Can an app tell me if I'm allowed to stay?

No app can, and ours doesn't try. It counts your days against each rule as published and shows its working. The authority at the border, the Home Office, the IRS or your adviser decides.