
I never had to face this situation with the sale of our puppies. Thankfully because for me, there are two main problems with people working nights
1. Left alone (and don't believe dogs know their owners are out, whether by day, or night) a puppy especially may well make a ton of noise and unlike during the day, would annoy neighbours - plus puppies need to be taken out once at night, at first.
2. If an owner works nights, they need to sleep during the daytime when any dog, puppy or adult doesn't! Unless they've been shouting all night of course....! So what time is there for the needs of a dog, especially a puppy who should need to be taken out roughly every hour when awake during the daytime.