Schengen days vs country-specific stays: one ledger, many questions

The Schengen area shares an external border, but day-count questions can be both regional (90 days in any 180) and national (time in France vs Germany). Your stay records should reflect actual country of presence so you can aggregate per country or per trip.

Rolling 180-day windows are awkward in spreadsheets. A dated list of stays lets you or a tool compute overlaps with arbitrary intervals, including Schengen-style windows, as long as each day is assigned to one country at a time.

If you bounce between Schengen and non-Schengen states in one trip, split stays by country and date range. That keeps per-country totals meaningful.

Immigration officers may use different evidence than tax authorities. Your app supports planning and consistency; carry correct visas and follow border rules independently.