[time-nuts] What is UTC after all?

[Didier Juges]

Looking at the Thunderbolt manual, I came across this:

<quote>
It is important to remember that any real-time UTC is actually a 
prediction of UTC.
The official UTC time is published approximately one month after the fact.
</quote>

It makes sense that real-time "UTC" is a prediction, since UTC is the 
average of a number of clocks around the world, we can't know ahead of 
time what they are going to do, we can only guess.

However, it is amazing to me that it takes a month to have the official 
time, which I guess is published in the form of an error from the 
predicted number.

That reminds me when Motorola went after the Malcolm Baldridge award, 
they looked at their processes and someone noticed that while FedEx 
could deliver a piece of paper or hardware across the country overnight 
as long as you call them before 4:00 PM, it took Mot 9 weeks to issue a 
check for that transaction, which involved many more people than it took 
to carry the package.

Here, we need a month to find out how many nanoseconds we were off... 
That's a lot of data to keep track off if you actually need the ultimate 
accuracy. I would not want to be the one counting nS for a month...

Didier