zero dark thirty

zero dark thirty

A non-specific time in the early morning before the sun has risen. Based on the way in which military time is said aloud. Why on earth are we meeting at zero dark thirty? The only thing we should be doing at this hour is sleeping! We'll have to leave at zero dark thirty if we want to reach Las Cruces before sundown.
See also: dark, thirty, zero
Farlex Dictionary of Idioms.
See also:
  • at one time or another
  • any time means no time
  • any day
  • any old time
  • against time
  • against the clock
  • any time
  • (it's) time to run
  • anytime
  • (it's) time to push along