Dark, light mode change by formula

[Ratatosk]

I’d like to have the app change to dark mode at sundown and vice versa. Preferably by formula.

[Hayden]

AppSheet does not currently have the ability to apply Expression logic to app theme. The closest available function would be Format Rules, which are usually applied to individual units of text or icons https://help.appsheet.com/en/articles/948896-format-rules-the-essentials.