• Definition Of A T-Minus List. A T-minus list is a checklist of items with a date attached. The date is set relative to the event that is at the end, and you schedule the tasks based on the lead time for the event. For example, if you made a checklist for producing the monthly newsletter at work, the event date would be the publication date.
• 3) minus x plus = minus (-2) x (2) = -4 4) plus x minus = minus (2) x (-2) = -4 These two are exactly the same, just as 2 x 3 = 3 x 2 This means that for example in -6 x 6, you have added negative six to itself six times.

• T Minus 1 Hour

T Minus 1 Hour

Best Answer: T minus zero 247 up, 17 down 'T minus zero' means 'out of time.' This comes from a countdown convention used in by both the American military and NASA. Generally, it is used when counting down to a major event that will happen at a specific time. Mathematically, T is time, minus whatever amount.

Image above: Spectators gather on the grounds in front of the countdown clock during a space shuttle launch. Credit: NASAThe countdown clock is one of the most-watched timepieces in the world. On this page, you'll learn how the countdown operates, and what milestones to watch for during our live launch coverage.Pauses in the countdown, or 'holds,' are built into the countdown to allow the launch team to target a precise launch window, and to provide a cushion of time for certain tasks and procedures without impacting the overall schedule. For the space shuttle countdown, built-in holds vary in length and always occur at the following times: T-27 hours, T-19 hours, T-11 hours, T-6 hours, T-3 hours, T-20 minutes, and T-9 minutes.Here are some of the key events that take place at each milestone after the countdown begins.