Privacy Policy
Last updated: November 2026
1. Who we are
TattwaCalendar ("we", "us") is a calendar app for iPhone, iPad, Apple Watch and Android that shows the Tattwa periods calculated from sunrise at a place you choose. This policy covers the app and this website. The developer responsible for the app is Carlos Enrique Clavijo Schmiedl.
Contact: digitalgo3msc@gmail.com
2. The app
The calendar works without an account and without sending us what you enter. We do not receive your activities, categories, reminders, places or settings.
- Activities, categories and settings are stored only on your device, in the app's own database and preferences.
- Location: if you allow it, the app reads your location while it is in use, only to calculate sunrise, sunset and the Tattwa periods on your device. Your location is not sent anywhere. You can choose a city instead.
- Calendars on your device: if you allow it, the app reads the calendars on your device (for example Google or iCloud accounts) to show their events with their Tattwa context. It never changes them, and the events stay on your device.
- Reminders and Tattwa alerts are local notifications scheduled on your device. The app does not use push notifications.
- Apple Watch: your iPhone sends the calculated Tattwa periods to your watch through Apple's watch connection; the watch keeps them on the watch.
- Widgets show the Tattwa periods and your next activities. The app passes them to its widgets on your device; they are not sent anywhere.
- No analytics, advertising or tracking. The app contains no analytics, crash reporting or advertising and does not track you.
3. The optional account
You can sign in with Apple or Google, for example to keep Premium on more than one device. Signing in is optional; the calendar works the same without it.
- What we receive: your name and email address as Apple or Google give them (with Apple's "Hide My Email" this is a relay address), the sign-in method you used, and an account ID created for you.
- Where it is kept: in Firebase Authentication and Cloud Firestore, services of Google. The account profile in Firestore (name, email, sign-in methods, dates) is stored in the European Union. Firebase Authentication may process data outside the EU under Google's safeguards. See the Firebase privacy information.
- Why: to sign you in and to attach Premium to your account. We do not use it for marketing and we do not share it.
- Sign-in tokens are kept by the Firebase software in your device's secure storage, not by us.
- Premium given by us: we can grant Premium to an account manually (for example for a tester). That grant is stored with your account ID. A record of each grant or revocation (time, action, the admin) is kept for security.
- Signing out leaves your account and the data on your device untouched.
5. Other services the app contacts
Besides the account and Premium, the app goes online only for the features below. In every case your device talks directly to the service; nothing passes through us.
- Searching for a city: the name you type and the app's language are sent to Nominatim, the place search of OpenStreetMap, operated by the OpenStreetMap Foundation. Like any web service it sees your IP address. See the OpenStreetMap Foundation privacy policy. Time zones are worked out on your device.
- Calendar subscriptions: if you subscribe to a calendar by its link (iCal, https:// or webcal://), the app downloads it from the address you entered, when you add it and when it is updated. The provider of that calendar sees your IP address, as when you open the link in a browser. An imported .ics file is read on your device only.
- Public holidays: if you add a country's holidays, the app downloads that country's public holiday calendar from Google (calendar.google.com), when you add it and when it is updated. Google sees your IP address. See the Google privacy policy.
- New versions: once per app session, the app asks the App Store or Google Play whether a newer version is available. The request contains the app's identifier, its language and your country (to pick the store), and the store sees your IP address. See Apple's privacy policy and the Google privacy policy.
6. This website
- Hosting: this website is served by Firebase Hosting (Google). To deliver the pages and keep the service secure, the hosting provider processes technical data such as your IP address, the page requested and your browser's user agent in its server logs.
- No cookies, no analytics: this website sets no cookies and uses no analytics or tracking. Fonts and images are served from this website itself.
- Choices you make (light or dark, language, the place in the live Tattwa display) are remembered in your browser's local storage, on your device only.
- "My location": if you use it, your browser gives this page your location to calculate the Tattwa periods in your browser. It is not sent to us or anyone else.
- Email: if you write to us, we use your address and message only to answer you.
7. Retention
- Data in the app stays on your device until you delete it in the app or remove the app.
- Your account (profile and any Premium we granted) is kept until you delete the account.
- Grant records are kept for up to 24 months for security. When you delete your account they are kept without your name, email or account ID.
- Purchase information at RevenueCat is kept while it is needed for your subscription and for our accounting obligations; you can ask us to delete it. Apple and Google keep their own purchase records.
- Emails you send us are kept as long as needed to answer you and then deleted, unless the law requires us to keep them.
8. Deleting your account
You can delete your TattwaCalendar account at any time:
- In the app: Settings › Account › Delete account. You may be asked to sign in again to confirm.
- Without the app: write to digitalgo3msc@gmail.com from the email address of your account, with the subject "Delete my TattwaCalendar account". We delete it within 30 days and confirm by email.
What is deleted: your sign-in account, your profile (name, email, sign-in methods) and any Premium we granted to you. With Apple sign-in, the app's access to your Apple ID is revoked as well.
What is kept: the data on your device (your calendar keeps working without an account); records of past Premium grants, without your name, email or account ID; purchase information at RevenueCat as described above, unless you ask us to delete it too. Deleting the account does not cancel a subscription; cancel it in your App Store or Google Play account.
9. Your rights
Under the GDPR and similar laws you have the right to access, correct and delete personal data we hold about you, to restrict or object to its processing, and to data portability. To exercise them, write to us at the address below. Data that only lives on your device you control directly. You also have the right to lodge a complaint with a data protection supervisory authority.
10. Changes
If the app or this website changes how data is handled, we update this policy and the date at the top.
11. Contact us
Questions about privacy: digitalgo3msc@gmail.com