Open 24 hours a day, including holidays.
There are many lanes where you can do a self-checkout. Some require that you not unload everything in their lane. You can do it, but you may be standing in line behind someone who has more "stuff" to unload than you.
Oh - and you can pay now or later, it's up to you.
Just keep in mind what you put in your cart.
You will pay for it one way or another, so live faithfully and enjoy life.
See you at the check-out!