By downloading or using Primordial Calendar you confirm that you have read and agree to these terms. Last updated: 8 August 2026.
This agreement is between you and the developer of this app, not between you and Apple. The developer, not Apple, is responsible for the app and its contents.
We grant you a non-transferable licence to use the app on any Apple-branded device that you own or control, as permitted by the Apple Media Services Terms and Conditions, for personal, non-commercial use.
You may not resell, rent out, reverse engineer, decompile the app or extract its source code.
The app provides calendar information: the 24 solar terms and 72 pentads, lunar dates, sunrise, sunset and daylight length, and conversions of the birth time you enter under the rules of the traditional calendar. These are reproducible astronomical and calendrical calculations.
Any interpretive text in the app is offered for cultural reference and self-reflection only and does not constitute medical, investment, legal, marital or any other significant life advice. Please do not make important decisions on the basis of it.
Calendar data comes from published astronomical algorithms. We work to keep it accurate but make no guarantee of absolute accuracy; to the fullest extent permitted by law the app is provided “as is”.
Results depend entirely on the birth time and place you enter. A wrong time, a mismatched time zone or a different daylight-saving convention will produce a different result. Please check your input.
Paid items in the app are one-time consumable purchases, priced as shown in the App Store.
Purchases are completed through the App Store and refunds are handled under Apple's policy; please request refunds from Apple, as we cannot issue them directly.
If content you have paid for fails to be delivered for technical reasons you are not charged twice, and retrying the same item costs nothing further.
Maintenance and user support for the app are provided by the developer at wangjingyucupl@gmail.com. Apple has no obligation whatsoever to furnish any maintenance or support services for this app.
To the extent permitted by law the app is provided without warranty of any kind, express or implied. In the event of any failure of the app to conform to any applicable warranty, you may notify Apple and Apple will refund the purchase price (if any) for the app; to the maximum extent permitted by applicable law Apple will have no other warranty obligation whatsoever with respect to the app, and any other claims, losses, liabilities, damages, costs or expenses attributable to any failure to conform to any warranty will be the developer's responsibility.
In the event of any third-party claim that the app or your possession and use of it infringes that third party's intellectual property rights, the developer, not Apple, will be solely responsible for the investigation, defence, settlement and discharge of that claim.
You represent that you are not located in a country that is subject to a U.S. Government embargo or that has been designated as a “terrorist supporting” country, and that you are not listed on any U.S. Government list of prohibited or restricted parties.
You must comply with applicable third-party terms of agreement when using the app (for example your wireless data service agreement).
You acknowledge and agree that Apple and Apple's subsidiaries are third-party beneficiaries of this agreement, and that upon your acceptance Apple will have the right (and will be deemed to have accepted the right) to enforce this agreement against you as a third-party beneficiary.
If these terms change we will update the date at the top of this page. Continued use after a change means you accept it.
For any question, write to wangjingyucupl@gmail.com.