I noticed that no community members have jumped in on your topic, so I’d be happy to take a stab at it.
Although a timed automation isn’t something that we’ve released per se, you’re on the right track with using formulas for this. In this case the “when a record enters a view” would be the desired trigger here.
Next create a filtered view where records filter out based on a specific date field (that could include NOW() or a similar formula).
When the desired date or time is reached, the record is filtered out and the automation fires.