i adopted a cat from a shelter and for the first few days he went in the litter box with no problem. Now when everyone is in bed he pees on the floor. It only happens when everyone is asleep. Even when we are all gone during the day he doesnt have an accident. Only at night when everyone is sleeping. Just wondering how to get him back into using the litter box at night.

Take your cat to the vet., could have a urinary problem or try getting another litter box and placing it where the cat usually sleeps

Take him to the vet to make sure nothings wrong with him. Usually cats will do that to say they have a problem. Try placing a new litter box in the spots where he pees the most.

Been owned by cats all my life.

You don't say how old the cat is, but it's not at all uncommon for recently adopted cats and especially kittens to feel anxious to be away from their owners at night. Put a second litter box in your bedroom, even if it just has flat sections of newspaper in the bottom, and even if it's only when you go to bed at night. It beats cleaning it up off the floor.

Otherwise, you may have to confine him at night to whatever room his main litter box is in.

Good luck!