How long do oil lamps burn?

Oil lamps are slow burners, and they burn around ½ ounce of oil per hour. Thus, a gallon of oil can help you clock 500+ hours. However, the same also depends on the type of lamp used, size of the wick, spillage, height of the wick, and type of oil. Often using olive oil lamps will mean more smoke, and it will need trimming. If you draw the burning height of the wick, it may begin to burn the wick itself.