The door closes at night because that is when the most predators are out looking for food (defenseless chickens).
If you’re tired of seeing auto-doors and want something simple, don’t have time nor money to waste, this design is for you.
You may need a small spring to keep it in place. its a good idea . a small spring added to the hinge and door you will not have to be slammed it
That would make a nice cheap option for some pullet for a grow out pen before combining them to an established flock