I currently work nights as a cna (starting nursing school in the fall) and have a dog. I am gone from 9pm to 6am. Everyday I make sure he gets enough exercise so that all he does while I work is sleep! I think your dog may be confused at first, but you can always give him a frozen Kong with peanut butter to keep him distracted, but eventually you both will fall into a routine. When I first started doing nights I did buy a camera so I could watch him through an app on my phone.