What is O Dark Thirty?
1.
Early in the morning before the sun is up.
Used to define when you must get up and go somewhere in the early hours of the morning between 1:30am and 5:30am.
a time in the am around the half hour mark.
"You're leaving tomarow? Will I get a chance to see you?"
"Nahh, we're taking off at o dark thirty. You won't be up yet."
See