Data and purpose
Entered dates are used only to calculate the result. They stay temporarily in browser session storage so your work survives page navigation.
Privacy
Privacy
Dates are calculated in this browser. We do not ask for a name, passport, nationality or account.
Advertising and cookies
AdSense is prepared but does not load until you accept advertising. Rejecting keeps the calculator available and does not enable advertising storage.
Control and rights
Clear the session by closing the tab or restoring the example. Use the localised contact link for Chapa Lab privacy questions.