There's no real-world object or concept that could "destroy gravity." Gravity is a fundamental force of nature, and while we can manipulate its effects in some ways, we can't simply "destroy" it.
If you are referring to a specific fictional work where this term is used, please provide more context, such as the name of the book, movie, or game.
It's possible the "Gravity Destroyer" is a fictional device or weapon with specific properties, but without more information, I can't answer your question about its spinning duration.
