The system calculates time from the second a new chat was started until it was closed. Our chatflow is open 24/7, but we let customers know office hours are 9-17, so if the bot can't help they'll have to wait.
Now, in the reporting, there should be a setting "only calculate time between 9am and 5pm CET", since the work speed of our staff is actually much higher than reported by Hubspot if you take that into account.
So the gain would be accuracy.
It is not a solution to only activate chat when we are online.