Last updated 30 August 2026

Terms of Use

One Day is made and licensed by Xiaoguang Zhang. It is licensed, not sold, to you for use on Apple devices you own or control, under Apple's standard licence terms with the additions below.

The licence

Use of One Day is governed by Apple's Licensed Application End User License Agreement. Where these terms and that agreement differ, that agreement governs.

The free week and the purchase

One Day is free to use for seven days from first launch. After that, writing new entries requires a one-time in-app purchase. It is not a subscription, it does not renew, and it stays with your Apple Account — including your Family Sharing group. Reading and exporting what you have already written remains available whether or not you purchase.

Payment is taken by Apple under its own terms. Refunds are handled by Apple at reportaproblem.apple.com.

Your content

What you write in One Day is yours. We claim no rights over it and, having no servers, hold no copy of it. Keeping backups — via iCloud or the Markdown export — is your responsibility.

What One Day is not

One Day is a journaling and planning tool. It is not medical, psychological, financial or legal advice, and it is not a substitute for professional care. If the questions surface something heavy, please talk to someone qualified. In a crisis, contact your local emergency services.

The protocol

The protocol One Day implements is adapted from a publicly published letter by Dan Koe. One Day is an independent app and is not affiliated with, endorsed by, or sponsored by Dan Koe.

Warranty and liability

One Day is provided "as is", without warranty of any kind to the fullest extent permitted by law. We are not liable for any loss of data or any indirect or consequential loss arising from its use.

Changes

These terms may change; the current version always lives at this address with its date.

Contact

[email protected]