Comment by rh-app-dev

The timestamp is based on the device. However, some of the security data comes from the Witness validation server and others from the platform (Google Play Integrity/Apple App Attest). Altering the date/time on the device would conflict with that information, and possibly fail the device validation. One of the key criteria for using the app is it will only run on a device that passes validation from the platform. So rooted devices can't run the app, as they can't pass validation.