Day Clock is a simple web app that lets you repurpose an old smart phone, tablet, or computer to display the current time, the part of the day, the day of the week, and the date. Just point your device's web browser to:
https://ryandesign.github.io/dayclock/
or for older devices without https support:
http://ryandesign.com/dayclock/
Any screen size is supported in portrait and landscape orientation. There are no settings. JavaScript must be enabled. Localization into languages other than English depends on the capabilities of your web browser.
On iOS or iPadOS, you can add the page to your home screen for a full-screen app-like experience. To do this, first open the page into Safari, then (depending on the Safari version) press the Action/Share button or the Add button.
Keep the device on a plugged-in dock, cradle, or stand and configure your device not to put the screen to sleep.