Head chefs typically have salary and their hours depend on the needs of the restaurant and their team. If someone calls out or doesn't show up, the chef needs to step in to support their team. But if your team is strong and reliable you can be home earlier than most industry folks.
Remember that fun weekend evenings are prime times for people to eat out, so service industry folks typically have their weekends during the week. It can be hard to keep in touch with friends and romantic partners who work standard office job hours when you're always at work whenever they're off, and vice versa.