That worker's hourly wage is a small fraction of the cost of just running the gas station at that hour of day. It costs money to run the lights, the refrigerato

That worker's hourly wage is a small fraction of the cost of just running the gas station at that hour of day. It costs money to run the lights, the refrigerators, and the gas pumps. The owner of the property doesn't charge less rent when the gas station is closed. Property taxes are still due. If the labor cost of the graveyard shift doubled the total cost of operations for that shift would increase only marginally. That gas station is only going to shut down for that shift if there's a significant change in costs. A small increase is completely covered by a single late night or early morning fill-up.