The steps for scheduling an action to occur at a specific time would be identical to creating an automation that does the same thing.
Although an automation can’t delete itself (there’s no deletion action) it can disable itself.
If you’re interested, the same WTH was posted 2 years ago and I provided blueprints for “One Shot” automations (perform a scheduled action and then disables itself).
It may also be possible to create a custom intent for the Conversation agent so you can say “Turn on something at time”.