[time-nuts] Another leap second problem

[Steven Sommars]

Recently a popular NTP/GNSS server began displaying an upcoming leap second
notice  <https://community.ntppool.org/t/leap-second-in-october-2026/4132/8>
.
That date is slightly less than 351 days in the future.  If my math is
correct,that corresponds to Sunday, 2026-10-25 00:00:00.
The NTP server support team has reproduced the problem and is investigating.

There was a leap seconds incident
<https://community.ntppool.org/t/leap-indicator-set-beginning-2021-11-27-00-00/2253>in
2021. Look at these dates:

1792886400 2026-10-25 00:00:00  Date advertised by NTP server.   (first
column is seconds since Unix Epoch)

1638057600 2021-11-28 00:00:00   Another leap seconds incident
<https://community.ntppool.org/t/leap-indicator-set-beginning-2021-11-27-00-00/2253>


1483228800. 2017-01-01 00:00:00  Previous leap second

These dates are each separated by 256-weeks.    There is a description of a
256-week bug at http://www.leapsecond.com/notes/leapsec256.htm

How widespread is this?   Commercial grade GPS simulators are expensive.
Could one build an SDR-based simulator on the cheap to test for such
problems?

Steve Sommars