I’ve been using an app called Coax (Apple only, which will disappoint some) to do this with my Plex library and it’s glorious. Beautiful retro styled schedule grid, automated channel/schedule creation, even has a weather channel with Jazz playing. I’m rediscovering stuff that’s been sitting idle on my server for years because it’s just fun to see what’s “on” and be like, ‘Oh yeah, let’s check that out for a few minutes’ and then I end up watching the whole thing.