On extended travel jobs, do you bill for non-working weekend days?

Curious what the standard is for extended gigs (2-3 months in my particular upcoming case). Do you bill for non-working weekend days? No bill, but hotel and per diem is covered? Go home every weekend if domestic? (My upcoming case would be international, roughly 24 hour travel one way, so....). Would it change if travel is couch vs business class (again, international, so huge difference).

FWIW I'm single and have no particular ties to my home city, but if trips home every X days/weeks are standard, I might want to visit my old home city.