Oscar Mike to the glossary. Copy that.
Military slang for an unspecified time in the very early morning hours, well before dawn. It is the hour when only insomniacs, new parents, and the military are awake. The name itself sounds like a horror movie, which is appropriate because waking up at that hour is genuinely terrifying.
Military designation for Coordinated Universal Time (UTC), formerly Greenwich Mean Time, allowing global forces to coordinate without time zone confusion. When it's 1400 Zulu, it's 1400 Zulu everywhere.
The exact time an operation or attack is scheduled to commence. Missing zero hour is a great way to ensure your carefully planned assault becomes a very expensive camping trip.
An unexpected release from scheduled physical training or duty, usually announced at formation to the delight of assembled troops. The rarest and most cherished gift from leadership.