Healthcare scheduling for practices and therapists

Why a booking can be health data

A booking for "Psychotherapy intake" with a name and email address attached tells anyone who sees it something about that person's health. Under Article 9 GDPR that is special-category data. Processing it is prohibited unless one of the conditions in Article 9(2) applies, and you also need a legal basis under Article 6. As the practice, you are the controller and make that call; a booking tool can't make it for you.

Keep diagnoses out of titles and questions

Name event types by format, not by condition: "First appointment, 45 minutes" instead of "Back pain assessment". The event type name appears in the confirmation email, in the reminders and in your connected calendar, so it travels further than you might expect.

Keep custom booking questions to what you need to arrange the visit: name, email, perhaps a phone number. Avoid a free-text field like "Reason for your visit", because people will describe their symptoms in it. Clinical details belong in your patient records, collected at the appointment.

Retention and patient requests

Completed appointments are deleted automatically after a retention period you set. The maximum is 90 days on Personale and Professionista, 180 on Team and 365 on Business and Enterprise. A shorter period is usually enough, because the booking record is not where you keep anything clinical.

If a patient asks for their data, or asks you to delete it, email info@kalendarius.com. We can send you an export of their bookings, or anonymise them by email address: name, email address, notes and consent time are removed. The rest of the record (time, status, answers to custom questions, cancellation reason) is deleted at the end of your retention period. Events already written to a connected calendar stay there.

Approval, reminders and no-shows

If you want to check new patients before confirming, make the link require approval. The request stays pending until you approve or reject it.

Once confirmed, the patient gets an email with a calendar file and links to cancel or reschedule, then reminder emails 24 hours and 1 hour before. In the dashboard you can mark each appointment as completed or as a no-show, or cancel it with a note to the patient.

If several practitioners share the work, round-robin links (included from the Team plan upwards) give each booking to the free practitioner with the fewest bookings on that link.

Where the data goes

The Kalendarius application and database run on Hetzner servers in Nuremberg and Falkenstein, Germany. Hetzner's data centres hold ISO/IEC 27001 certification; that is Hetzner's certificate, and Kalendarius itself holds no certification.

Hosting in Germany covers our part. If you connect Google Calendar or Microsoft 365, those providers process the appointment under their own terms, which is one more reason to keep event names neutral. An email delivery provider sends the confirmations and reminders. Public booking pages load no advertising or analytics trackers; we do run Sentry error monitoring there to fix bugs. Our terms require Business with a signed DPA before you process health data through Kalendarius. A Data Processing Agreement (DPA) for the Business and Enterprise plans is in legal review; contact info@kalendarius.com.

Your data protection officer will want the same answers from every vendor you consider. Our checklist for GDPR-compliant scheduling software lists the questions to ask.

What Kalendarius doesn't do

Kalendarius is a booking tool, not practice software. It holds no clinical notes and handles no insurance billing. It can't take payments at booking, book treatment rooms, or send SMS reminders, and there is no mobile app. Reminder times are fixed.

Primary sources

The legal points above are based on the GDPR text, Articles 6 and 9. When you assess a connected Google or Microsoft calendar, the European Commission's guidance on international data transfers explains the rules in Chapter V. Hetzner's certificate is described on Hetzner's certification page. Sources checked 20 September 2026.