[time-nuts] Leap second to be introduced at midnight UTC December 31 this year

Martin Burnicki martin.burnicki at burnicki.net
Wed Jul 20 06:45:39 EDT 2016


Magnus Danielson wrote:
> Now, what annoys me is that the IERS message says that the leap second
> is scheduled for January:
> 8<---
>                                               Paris, 6 July 2016
>                                               Bulletin C 52
>  To authorities responsible for the measurement and distribution of time
>                                    UTC TIME STEP
>                             on the 1st of January 2017
>  A positive leap second will be introduced at the end of December 2016.
>  The sequence of dates of the UTC second markers will be:       
>                           2016 December 31, 23h 59m 59s
>                           2016 December 31, 23h 59m 60s
>                           2017 January   1,  0h  0m  0s
> --->8
> It is unfortunate that it says UTC TIME STEP on the 1st of January 2017,
> as it is scheduled for 31 December 2016.

Hm, the leap second is inserted at the end of December 31 (which is also
said by the message text), but as a consequence the beginning of January
1 is delayed by 1 second, so IMO this statement might be correct, even
though it's not formulated very clearly.

> This is a new habbit of IERS, and it is unfortunate and not helpful.
> Older Bullentin C used the more correct reference to end of June or end
> of December.

Hm, the oldest bulletin C I found on the IERS web site already has the
same statement:

I find it amusing that until ~2011, if no leap second was scheduled, the
message text said:

"NO *positive* leap second will be introduced ..."

If you're nitpicking you could have expected that eventually a
*negative* leap second was to be scheduled. ;-)


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