answer:I have no idea when it comes to kittens. When we adopted my grandmother’s seven-year-old cat, we kept him inside for about ten days. We then showed him around the garden using a leash. We did this every day for about three days. One night, at midnight, he wanted to go outside (this was about two weeks after we originally got him). My mum let him out. He returned at ten o’ clock the next night. I’d say two weeks is a good time period to keep it indoors. And then slowly introduce it to the outside world. :-) I hope this helps.