I believe in absolute power for the classroom teacher. There's no democracy, and no discussion about some things. For example, in the trailer, I might let the kids out a few minutes early so they can slog through the wind and snow back to the classroom. Nonetheless, I get to make that call, and if they have to stay till the bell rings, or even after, well, so be it.
So when kids say, "It's time to go," it irritates me to no end, and I tend to make them stay while I go over some fine point of the lesson that doesn't really need going over. In fact, the more tedious I can make that last unnecessary moment, the better. Mostly they catch on and stop saying that. But some kids are hardcore and cannot be dissuaded.
So the other day, I tried something new. When the guy who didn't catch on said, "It's time to go," I said, "Fine, everyone can go." All the kids rose to leave, and I added, "Except you. You stay till the bell rings." He took it as a joke, and got up to leave. But when he set foot out the door, I told him there would be dire consequences if he didn't return to his seat instantly. He looked at my face and went back.
I gathered all my stuff, and discovered the bell was actually late that day. So I picked up my bag and told him, "I'm leaving. But you have to stay till the bell rings. If you get out of your seat before that, I'll know it, and you will regret it."
I walked toward the building. As I approached it, the bell rang, and I saw the kid run like a bat out of hell out of the trailer. And guess what?
He hasn't told me since when it was time to go.