Why would you even allow it?
"It" as in, the 24h grace period to finish the take on Summer of Suffering or other similar timed content, where all of the rewards are outside of the quest itself and are not prolonged together with it.
I planned it. I used a lot of resources. I had to spend two hours in my bank trying to stop a scammer halfway over the world from breaking into my credit card. I finished the round about five minutes after reset - and thanks to that policy feels like I might as well have been scammed anyway.
It makes sense in content that includes the prize but honestly, I'd rather be kicked out of the quest than lose more time and currency for literally nothing.