Years ago I used a Mac Mini as a DVR (EyeTV) and the software had a guide where you could setup recording analogous to Plex, but also simply specify a channel, date/start time and recording length. Why would I want such a thing? Sometimes you end up with delayed start times for shows because of sporting events running over their scheduled times. Another potential solution is to specify a recording be delayed a certain number of minutes before starting.
The guide never reflects these real-time changes. Also, I’ve seen the guide not correctly displaying a particular show.