CalDelta privacy policy
Short version: your calendar never leaves your phone. The only thing CalDelta sends anywhere is an anonymous push token and the time of day you asked to be notified. There are no accounts, no analytics and no advertising.
What stays on your device
CalDelta reads your calendars through Apple's EventKit, using the accounts already set up on your iPhone. Event titles, times, locations, notes, guests and which calendar an event belongs to are read on the device, compared on the device, and stored on the device. None of it is transmitted to IDST UK or to anyone else, and there is no server anywhere holding a copy of your diary.
To tell you what changed, the app keeps its own record of the events it has already seen. That record lives in the app's private storage on your phone. It is what lets CalDelta still describe an event that has been deleted, after the calendar itself has forgotten it. Deleting the app deletes that record with it.
CalDelta never creates, edits or deletes anything in your calendars. Removing a row from the list in the app removes only the row.
What leaves your device
If you allow notifications, two things are sent to a scheduling service run by IDST UK at
caldelta.idst.uk, hosted by Netlify:
- An Apple push notification token. This is issued by Apple and identifies one installation of one app on one device. It is not your name, your email address, your phone number or your Apple Account, and it cannot be used to look you up.
- The time of day you chose, your device's timezone, and whether the build is a development or production one, so the scheduler knows when, in your local time, to wake the app.
That is the complete list. The scheduler's only job is to send a silent, contentless wake-up signal at the right moment. It has no idea whether anything changed in your calendar, because it cannot see your calendar. The app works that out after it wakes, and writes the notification on the device.
How long it is kept, and how to remove it
The token and time are stored for as long as the app is installed and notifications are on. Turn notifications off for CalDelta in iOS Settings, and the app asks the scheduler to delete its record. Delete the app, and Apple stops accepting pushes for that token; the scheduler deletes the record the next time it tries. The lawful basis is legitimate interest: you asked for a daily notification and this is the minimum needed to deliver one.
What CalDelta does not do
No analytics or crash-reporting SDK. No advertising or advertising identifier. No tracking across apps or websites. No third-party libraries of any kind. No account, no sign-in, no email address. Nothing is sold or shared, because there is nothing to sell or share.
Children
CalDelta is rated 4+ and collects nothing that identifies anyone, of any age.
Your rights
Under UK GDPR you can ask what personal data is held about you, ask for it to be corrected, or ask for it to be deleted. In practice the answer is a push token you can delete yourself by turning off notifications. If you would like it confirmed or done for you, use the contact form with "CalDelta data request" in the message. IDST UK is the data controller. If you are not satisfied with how it is handled, you can complain to the Information Commissioner's Office at ico.org.uk.
Changes
If what the app sends changes, this page changes in the same breath. The date at the top is the date it was last true.