[LEAPSECS] BBC radio Crowd Science

[GERRY ASHTON]

> ...On January 31, 2017 at 7:08 PM Steve Allen <sla at ucolick.org> wrote in part:
> I prefer to think of a leap second as being truly intercalary.
> It is saying to atomic clock "It's not tomorrow yet, wait a second."
> It is between one calendar day of UTC and the next calendar day of UTC.
> It belongs to neither of them...

UTC is civil time. Civil time is used to express deadlines. Most deadlines fall at the end of a calendar day, so which day the 61st second falls in will only affect a few time zones, but deadlines may fall on other hour boundaries. So it is necessary to know which hour the 61st second belongs to, and I believe it belongs to the hour that is about to end.

Gerard Ashton