the exact time when an attack or other military action will start
The air force planes waited until zero hour in order to begin their bombing mission.
Strangest Prehistoric Creatures To Rule The Earth
About the size of a VW Bug, the Glyptodon was an armadillolike creature which actually would be more related to modernday turtles. Sporting over 1 inchthick (2.5 cm) scales, the Glyptodon was a herbivore and, unlike turtles, could not retract its head; instead, it had a bonelike cap on its head.