[LEAPSECS] Leap smear

[Tom Van Baak]

> Well, it has been that way for ages, and it's the very

> reason why UTC is defined as it is: to stay near UT

> within a small margin.


Ah yes, but how large should the "small margin" be? And why?

If you read the old papers regarding time scales and UTC you
get a hint what of the major motivation was. It was navigation;
specifically for sailors with sextants. That's why the margin was
originally 0.1 second. And that's also why the radio broadcast
folks got involved (you needed to communicate accurate time
and DUT1 to ships at sea, by radio).

But times have changed.

We now have GPS, VLBI, the web, sat phones, mobile phones.
No one relies on sextants and DUT1 radio broadcasts anymore.

It makes sense to address how large the "small margin" can be
from time to time to more efficiently serve the users of UTC and
to better reflect or take advantage of social and technological
changes.

Does it continue to have to be sub-second? Or would it be ok to
let the margin grow to a second, or two, or even 10?

/tvb