Buttcrack of dawn

Very very early in the morning, right before the crack of dawn.

God I'm tired, that damned dog woke me up at the buttcrack of dawn

Buttcrack of dawn by Blake November 11, 2002

butt crack-of-dawn 

early morning sunrise over the mountains

I've been up since the butt crack-of-dawn.

butt crack-of-dawn by Emmy November 25, 2003

butt crack of dawn 

An early time of awakening for those that usually get up around noon. Thus, the time would be something like 10-11 a.m. or so.

Lou: What time did you get up?
Stu: Today it was like the crack of dawn for me! Like 11 a.m.
Lou: Dude, that's more like the butt crack of dawn.

butt crack of dawn by Pie Lady February 15, 2006