How to use:
- December 1st, 2024 is set as your start date (highlighted with a blue ring)
- Click on dates to mark individual days spent in the country (will be filled in blue)
- Use Shift+Click to select a range of dates: first click sets the start (green ring), second click fills all days up to that point
- The calculator will check if you maintain at least 90 days of stay in every 180-day period, starting from May 29th, 2025 (180 days after start)
- If you don't have enough days in any period, it will show when this happens (date highlighted in red) and how many days you're missing
- Click a marked date again to unmark it
- Your marked days are automatically saved and will persist even if you close the browser
- Use the "Clear All Days" button to reset all marked days