That’s the “T-minus” countdown “T-minus 10 hours.” The closer the time of launch approaches, the more the countdown will be “T-minus 9 hours,” “T-minus 5 hours,” “T-minus 55 minutes,” etc., until it reaches the most iconic part of the launch countdown – the last 10 seconds before launch.

How do you write T minus in text?

T represents the time of an event. Therefore the correct usage is “T minus x minutes” (whether you write minus or – makes no difference).

Why do you say T minus when counting down?

T- (pronounced “T minus”) refers to the time remaining on the official countdown clock. The “T” stands for time. During planned holds in the countdown process (when the countdown clock is intentionally stopped), the T- time also stops. The L- time, however, is synced to the clock on the wall and continues to advance.

“T minus Time” is a system to mark points at which actions necessary for the launch are planned – this time stops and starts as various hold points are entered, and so doesn’t show the actual time to launch. The last ten seconds are usually counted down aloud “Ten seconds to liftoff.