graddis.org is a private family website. Google sign-in provides your name, email address and account ID, used only to sign you in and manage access. If you connect Google Calendar, your events are read to show them in the app.
Data is stored on graddis.org's servers. It is not sold, shared or used for advertising. Use of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.
Imported calendar events are kept only while Google Calendar is connected. Disconnecting in Calendar revokes access and deletes them immediately. Deleted data may remain in database backups for up to 30 days. To have any other data deleted, ask the site owner.