[ntp:questions] Lep seconds
unruh-spam at physics.ubc.ca
Fri Jan 4 18:20:55 UTC 2008
markn_46 at yahoo.com (Mark Newman) writes:
>Unruh - thanks for responding. You are the only one
>I certainly did not mean to disparage NTP time. I
>have spec'ed that it be used on our system. Where I
>run into problems is when a leap second occurs.
Since no leap seconds have occured in the past 2 years, and before that for
7 years, I doubt that you
have every seen a problem when a leap second occurs.
>According to everything I've read when NTP signals
>the operating system that the second is occurring it
>also outputs time. It uses the POSIX standard method
?? I have no idea what that phrase "outputs time" means.
>- duplicate a second (or in some cases stretch the
>last second). This causes confusion when a time
>sample is taken before the leap second and one during
>the leap second. The UTC standard (which only
>addresses ascii time representations) actually counts
>the second 0..60 rather than 0..59.
Yes. And since that one second occurs about once every 2-3 years, on Dec 31
or June 30, who cares. Again what is your problem that you are trying to
>At this point I am obligated to use UTC and NTP.
>Tht missing second is causing me to get a lot of heat.
>From whom? There is no missing second. Noone has seen a leap second in
quite a while. Who is giving you the heat? And if they do, explain to them
how UTC works.
> Does anyone know of a way to get NTP to count the
>leap second rather than to delete it? Or am I missing
???? I have no idea what you mean. Most leap seconds add a second to the
year-- Just as leap years add a day ( or do you also have trouble with leap
years, and want us to go on lunar time, which does not have them.)
>>I don't want to step on anyones toes but I am getting
>>a lot of heat over using a POSIX compliant ntp re
>>seconds. The 1 second error inserted can cause a lot
Again, heat from whom? You have never told us what problem you are trying
>Exactly what heat are you getting and what trouble is
>it causing you?
>Perhaps if you tell us the problem rather than your
>solution, we could come
>up with a solution.
>>I now that the Olsen mod changes most Unix/Linux time
>>processing to handle the leap second in a
>>theoretically correct manner rather than being POSIX
>I have no idea what "a theoretically correct manner "
>is. The Posix IS a
>theoretically correct manner.
>>compliant. Is there a similar mod for NTP. I am
>>hoping that there is a mod that will cause NTP to
>>supply theoretical UTC (even if it is not ascci).
>NTP DOES supply both theoretical and practical UTC.
>I think what you are worried about is that you want
>your system to provide
>something like TIA-- Atomic time-- which has no leap
>seconds. I believe the
>Olsen mods have your system clock run on atomic time
>and then use the
>leapsecond file and the zoneinfo file for your region
>to translate that to
>your local time.
>You could just set up ntp to add 33 sec to its time,
>and you would have
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