This illustration draws a contrast between behavior at night and behavior during the day. The apostle Paul listed a number of “works” commonly done at night: sleep, parties, drunkenness... There are people who live for this. They see the day as the means to gain the night, and sunrise is their gloom.
Bring the night works into the day and you just might lose your job... because day is about being productive. The Christian should live for the day, and see night as the means to gain the day. It is said that my wife, Carol's, great-great grandfather died at his plow while waiting for sunrise. May Jesus find us at our plows waiting for sunrise... because the night is far spent, and the day is at hand.