Stay180 is a Schengen short-stay planner. Add past and planned stays, see days used in the last 180, and get a leave-by date for your next trip. It catches traps spreadsheets miss: both border days count, “days left today” isn’t your trip length, and old stays age out so days come back. Free on-device calculator; Pro adds sync, calendar import, email alerts, and a printable border briefing. Planning tool only — not immigration advice. Verify with the official EU calculator before you travel.