burning daylight

Wasting time. Literally, losing valuable daylight hours (of which there never seem to be enough of).

Wasting time during hours when the sun is up. People were often only able to work when they could see outside.

Wasting time, hesitating when something should be done quickly. Literally, letting the day go by while you are waiting to get started.

A film industry slang term. Used as a way to tell actors and crew to hurry up as natural daylight wanes. Since the sun's position and quality changes throughout the day, sunlit shoots can be challenging to match later in editing, so it's important to get scenes done efficiently. This phrase is often used jokingly indoors to spur on the film crew.