To prevent this, keep cats indoors for at least two weeks after moving. Ensure your cat’s behaviour has settled before letting them outside. However I would give her at least 6 weeks to learn that your house is her house. When you do let her out, supervise her in the garden before letting her go out of sight.ow long that takes depends on the cat; it was a month before my two decided I was an acceptable human, and they're indoor cats. One thing I used to do with outdoor cats after moving was to go out with the cat the first few times -- walk them around the building while they check out the neighborhood and landmarks.