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Re: Setting seconds on a digital display
From: Bill B
Date: 2016 Sep 13, 17:03 -0400

```The following is from of NIST Special Publication 432, 2002 Edition.
NIST Time and Frequency Services, Michael A. Lombardi

Document pages 40 and 41, PDF page numbers 46 & 47.

http://tf.nist.gov/timefreq/general/pdf/1383.pdf

"UT1 Correction
UT1 corrections are encoded into the broadcasts by using doubled ticks
during the first 16 s of each minute. You can determine the amount of
the correction (in units of 0.1 s) by counting the number of doubled
ticks. The sign of the correction depends on whether the doubled ticks
occur in the first 8 s of the minute or in the second 8 s. If the
doubled ticks are in the first 8 s (1 to 8) the sign is positive. If the
doubled ticks are in the second 8 s (9 to 16) the sign is negative. For
example, if ticks 1, 2, and 3 are doubled, the correction is +0.3s. This
means that UT1 equals UTC plus 0.3 s. If UTC is 8:45:17, then UT1 is
8:45:17.3. If ticks 9, 10, 11, and 12 are doubled, the correction is
–0.4 s. If UTC is 8:45:17, then UT1 is 8:45:16.6. If none of the ticks
are doubled, then the current correction is 0."

Better late than never?

On 8/24/2016 2:23 PM, Greg Rudzinski wrote:
> Frank,
>
> Isn't the daily small fraction of a second remainder given a sign ? The
> next leap second is December 31 so I would think that the .25 seconds
> difference today is positive and to be added. By December the correction
> to be added will be about .5 seconds. After the new years leap second
> then .5 seconds should then be subtracted to getUT1.
>
> http://earthsky.org/human-world/leap-second-june-30-december-31-why-need-controversy
>
> Greg Rudzinski
>
>     So what about DUT? Checking
>     here http://maia.usno.navy.mil/ser7/ser7.dat, the value today is
>     about a quarter of a second. But somebody do the signs for me
>     (having trouble thinking this week...): if I am listening to UTC
>     time ticks on the shortwave, and I want my watch to show UT1 /to the
>     nearest second/, do I offset it 0.25 seconds or 0.75 seconds (half a
>     second for this setting issue and a quarter second for DUT, but
>     which way?).
>
>     Frank Reed
>
> View and reply to this message
>
>
>

```
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