How long should you keep your cats in the house after you move to a new home?

I was told two weeks. I have two cats and neither of them have ever lived in another home. We have lived here two weeks and I have taken them outside on a leash. They want outside really bad. I want to let them out but I want them to come back. They are both fixed. There are sooooo many cats around here. I'm afraid they are going to get beatin up.