The new year is just a moment in time invented by humans The correct year is around 13,800,000,000 and has no connection to January 1st  ?

Correct, but you know what humans are like, they love to relate things and memories to their own existence, they like it  that way. 13,800.000.00 is too far away, it has no linkage to their past, and is even further away from their tomorrows.

Our calendar is designed to allow us to measure the passing of time, nothing else, and to refer to specific occurrences in the past or future to determine when they happened or when they will happen.

Did you include leap years ?

You're close anyway .

We invented time ...

but we need a bit more precision than that don't we. the 100m world record is around 10 seconds :0

All I can say is:

but we need a bit more precision than that don't we. the 100m world record is around 10 seconds :0

OK, good.  Whatever floats your boat.

If you choose to look at it that way.  I'd say that to most of us it's more meaningful than a moment in time.

Agreed. But all we have to decide is what to do with the time we are here. 

https://www.youtube.com/watch?v=VGn-4yZFalY

Yeah time is largely a human invention, or at least the way we measure it is, yet we are still all bound to it whether we like it or not. Neat, eh?