What does T minus

Why does the T in T-minus stand for test?

Contribution from Faraday »

Hello,

A few days ago I asked myself why one actually gives the countdown for a rocket launch in the form, for example: T-5min
I found an answer on this page, but unfortunately I don't fully understand it. I hope you can help me

I am quoting from the original source and trying to translate it as I understand it
When you are in the firing room on launch day, we hear the terms "t minus" a lot during the countdown. What does the "t" stand for?
I joined the space program about 20 years ago and I asked this question of my, of my elders in the program when I did join, and it turns out that T stands for test. Because it's not always related to time. It could be the start of a particular test in our Orbiter Processing Facility that is independent of the time of day.
When we are in the firing room on the start day we very often hear the expression "T minus". What does the "T" stand for?
I joined the space program about 20 years ago and I asked this question to a manager when I started. It turned out that the "T" stands for "test" because it is not always related to time. It could be the start of a certain test in our 'shuttle hangar' which is independent of the time of day.
What I do not fully understand now is why it is called test and not called start.
It is counted down at the start of the rocket and after the start it counts in the positive direction. Then it says T + ...
Why could this be called a test?
Did I misunderstand something or was it not explained on this YahooAnswer page?


Thanks in advance for the help and
best regards,
Philip



Ps: I hope the links are ok. If not, I'll ziet the pages (if that's okay ).