I have worked every shift in the book.
Overnights 10pm-8am.... lasted on that for nine months.
Weekends 9am-7pm
Evenings 3pm-11pm or midnight
Days 9am-5pm or 10pm-6pm or 11am-7pm
Now I work noon-10pm, four days a week. But any four days. It changes every week. But I LOVE it.
The five days off at a stretch is nice. I think it'll be an adjustment but doable. The days (nights) he's doing overnights will suck, but I don't know what he'll be doing exactly. I know I needed to sleep 8 hours a day during the day when I was on overnights because it was the only way I could go on the radio every half hour and read a coherent newscast.
Maybe he'll be able to get by on less and be able to have supper with you or something? Or breakfast when he gets home? Good luck! Try not to worry too much...