Legal basis
Article 6(1) of Regulation (EU) 2016/399 (the Schengen Borders Code), as amended by Regulation (EU) No 610/2013, allows third-country nationals "intended stays on the territory of the Member States of a duration of no more than 90 days in any 180-day period, which entails considering the 180-day period preceding each day of stay."
The algorithm
- All stays are expanded into a set of calendar days. Entry and exit days are both included. Overlapping stays are counted once.
- For an evaluation date T, the reference period is
[T − 179, T]inclusive — 180 days. - Days used = number of presence days within that period. Days remaining = max(0, 90 − used). Overstay = max(0, used − 90).
- Next legal entry = the first date D ≥ T, not already a presence day, where presence in
[D − 179, D − 1]plus one ≤ 90. - Trip simulation adds the proposed stay and evaluates every day of it with its own window, reporting peak usage, the first illegal day and the latest legal exit.
- Full reset = last presence day + 180, the date your window is empty again.
Dates are handled as UTC calendar days so time zones and daylight saving changes cannot shift a count.
Matches the official tool
The method mirrors the European Commission's short-stay calculator. Our automated tests check standard cases such as a 90-day stay followed by re-entry exactly 180 days after the first day.
Limitations and disclaimer
- Bilateral visa waiver agreements, residence permits, long-stay visas and transit rules are not modelled.
- Results depend entirely on the dates you enter.
- This tool is not legal advice. Border authorities have the final say. Aurevon Group Ltd accepts no liability for decisions made using it.