[time-nuts] June 30 2015 leap second

Hal Murray hmurray at megapathdsl.net
Sun Jan 11 00:59:25 EST 2015

michael.cook at sfr.fr said:
> I haven’t looked at the raw data, but using the windows apps: 
> a Trimble Resolution SMT is showing the leap pending a Motorola UT+ is not.
> lady heather is not 

Interesting.  I don't see any leap-pending from a Z3801A.  (or a KS-24361)

There is another interesting worm in this can...  Various software in the 
chain from Paris to your PC may filter the leap-pending info.

There was at least one bug in ntpd where it told the kernel to leap-tonight 
several months early.

The way it's supposed to work is that ntpd tells the kernel leap-tonight, and 
the kernel will add/delete a leap second at midnight.  That gives the ntp 
servers a whole day to propagate the leap-pending info to lower stratum 
servers and another day to turn it off by the next midnight.

The T2 string from HP GPSDOs includes a slot which is +, -, or 0 for insert, 
delete, or none.  You can ask it when the leap is scheduled, but the code 
didn't do that.  It just assumed the leap was scheduled for the end of the 
current month.  The fix was to add a filter to only pay attention to that 
flag in June and December.

These are my opinions.  I hate spam.

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