This policy covers the primcal.tech website and the Primordial Calendar iOS app. No account is required, and we do not collect your phone number, email address or social accounts. Last updated: 8 August 2026.
What you enter: your date of birth down to the minute, your place of birth and your sex. These are used only for calendar arithmetic — turning the shared calendar of solar terms and lunar dates into the one that belongs to you (the sexagenary characters for the day you were born, how far apparent solar time runs from clock time where you were born, which zodiac year you fall in under each of the two conventions). Sex only determines the forward or backward direction used by the traditional calendar.
What you may leave blank: the label you give a profile, and the question you type when you use a paid deep reading.
What is generated automatically: on first launch the app creates a random anonymous device identifier locally, used only to validate in-app purchases and to prevent abuse. It is not an advertising identifier, it is not tied to your identity, and reinstalling the app generates a new one.
We do not collect location, contacts, photos or health data, and we do not perform cross-app tracking or serve advertising.
Birth details are used to perform and display calendar conversions on your device.
When you purchase and use a deep reading, the converted result, the profile label you entered and the question you typed are sent to our server and forwarded to a third-party AI service to generate text, which is then returned to your device.
The device identifier is used to validate in-app purchases with Apple and to rate-limit requests per device to prevent abuse.
On your device: profiles and generated content are stored locally only, and deleting the app removes all of it.
On our server: we require no sign-in, build no user profiles and do not retain generated text. To stop a single purchase being redeemed twice we keep one validation record containing no birth details; it expires and is deleted automatically after 3 days.
A third-party AI service (DeepSeek): receives the content described above, only when you use a paid deep reading, in order to generate text.
Apple: in-app purchases are processed and validated by the App Store. We never receive your payment method, card number or Apple Account.
Beyond the above we do not sell, rent or trade your information to anyone; we disclose it only where the law clearly requires it.
Deleting the app clears every profile and all generated content from your device.
Solar-term reminders can be switched off in the app at any time, and in Settings → Notifications at the system level.
There is no account system on our server, so there is no long-lived user record to look up or export. If you would like us to confirm or delete any residual record, write to wangjingyucupl@gmail.com and we will respond within 30 days.
This app is not directed to children under 13 and we do not knowingly collect their information. If you believe a child has provided us with information, contact wangjingyucupl@gmail.com and we will delete it promptly.
If this policy changes materially we will update the date at the top of this page and note it in the app.
For any privacy question, write to wangjingyucupl@gmail.com.