It is actually o' dark-thirty. It is a military term refering to beinging somewhere before the sun rises
We have to go, we have PT (physical training)at 0' dark-thirty.
by Goldi December 21, 2005
the thirty minutes before nightfall, or the thirty minutes after night falls.basically the 1 hour time frame as it becomes dark.
i told david the party starts at dark-thirty.
by da trick biatch December 20, 2005
Something hicks from illinois say when they're referring to the time right after the sun sets.
Be home before darkthirty ya'll.
by AlissaGrace April 01, 2005