@kytta Two years ago, I used #FullPageOS for a project and was happy with how easy it was to set up :raspberrypi:
You give it a list of webpages and it can headlessly launch them after boot in a fullscreen Chromium instance.
IIRC you can set the duration between webpages to an arbitrary value (e.g. display every webpage 30s or 1h)
Last Release was in May of last year, so I'm not sure, if everything still works and is safe to use, but you might want to give it a try:
github.com/guysoft/FullPageOS