Contact us
Email [email protected]. The app’s Support button automatically adds the version, platform and language without attaching your calendar or notes.
What does FrontierDay count?
The app counts days you classify as worked in France or another country. A day or part-day worked outside Luxembourg may count as one full day. Days marked “Not working” are excluded.
The 34-day threshold is a reference value, not a guaranteed allowance. It may be reduced for part-time work or employment covering only part of the year.
What happens when the threshold is exceeded?
FrontierDay shows a warning but does not calculate tax. Under the general rules, exceeding the threshold may have consequences from the first day worked outside Luxembourg, not only from day 35. Confirm your position with an adviser or the competent authority.
Where is my data?
Your calendar and notes remain in the device’s private app storage. There is no account or sync service. Uninstalling the app therefore also removes its local data.
How do I save or share my calendar?
Open the menu and select “Export CSV”. FrontierDay creates a local file that you can save or share with an app of your choice. Always check the recipient: the export may contain private notes.
My local file is damaged
FrontierDay quarantines an unreadable file and opens an empty calendar so it does not overwrite the damaged copy. Do not add new entries before contacting support.
Tax scope
FrontierDay is a tracking aid for French residents who normally work in Luxembourg. It does not cover social security, determine tax residence or replace professional advice. Third countries, public-sector work and personal circumstances may require a specific assessment.
Main reference: official Luxembourg circular dated 24 June 2026.