The phrase paints a picture of the earliest morning light appearing.

Imagery Use

It specifically refers to the time just before or as the sun rises.

Time Specific

May suggest dedication or strong commitment to an activity.

Highlights the start of a day's activities, often ones that cannot wait.

Implies a time of day when the world is often still and quiet.

The phrase can express a sense of reluctance or hardship.

Used to stress the extremity of waking very early, perhaps humorously.

Can highlight the discomfort of waking earlier than usual.