crack of dawn(redirected from crack of day)
the crack of dawn
The moment at which the sun first rises. It's a long drive, so we'll have to leave at the crack of dawn if we want to get there on time. I've been up since the crack of dawn repairing the fences that blew down in the storm.
crack of dawn
Very early morning, daybreak. For example, I got up at the crack of dawn. The crack in this term alludes either to the suddenness of sunrise or to the small wedge of light appearing as the sun rises over the horizon. Originally the term was usually put as crack of day. [Late 1800s]