On 2014-12-13 19:28, Harlan Stenn wrote:
Brian Inglis writes:
On 2014-12-12 03:25, Harlan Stenn wrote:
It's pretty easy to download and install a leapsecond file, and ntpd
will pay attention to that...
Not that easy - unless you are one of the lucky few to have encrypted
access to a NIST source, when it may be automatic.
http://www.ietf.org/timezones/data/leap-seconds.list
Well aware of that source, as I said, and you trimmed:
OTOH the timezone/zoneinfo package uses its own leapseconds file (for "right"
time - now zoneinfo-leaps), and distributes that and the original, a script
that checks and converts it to their own format, and utilities that use it.
but not exactly widely known as a source, unless one subscribes to that list.
Many time server operators outside the US may be unaware of where to find
NIST servers and the leap-seconds.list file.
When deprecated Autokey is replaced by Network Time Security, there does not
seem to be any mention of including leap seconds distribution as part of the
new functions, from what I have been able to read so far. This would be a
useful addition and may be an essential requirement if times need to be
within a second, or legally useful.
For something that is critical to correct timekeeping, and puts a proportion
of servers over the step threshold every 18-24 months, updating leap seconds
should be part of the normal time service protocol, or an adjunct, not just
encrypted connections to NIST servers, or a manual or custom process, available
from only a few sources, all in the US, which may be blocked in some countries.
Global availability and better distribution of leap second information for
use by time servers should be considered an essential service and source
by anyone who relies on those servers for legal time, such as financial
traders.
Legal civil time in most countries is defined as mean solar time, where it
is not still defined relative to GMT, as it is in most countries in the
Commonwealth of Nations deriving their common laws from England, and many
allied European and Asian countries. This can be validated from the posts
of official time change notices referenced on the timezone list.
Any departure of timekeeping from legal civil time will be viewed
negatively by the courts, as it has in past precedents.
The opinions of astronomers and physicists, who picked a century out of
date value by solar standards when they defined the second, along with
an incremental update approach that was used for a few years before being
discarded in favour of using leapseconds, are insignificant compared to
the politicians and courts who change and interpret legal definitions,
which require noon to be, in the mean, about the same solar time each day.
I am somewhat surprised that no lawyer has, as yet, argued for phone evidence
to be discarded because telco equipment uses TAI or GPS time scales which have
no legal basis in any country.
--
Take care. Thanks, Brian Inglis
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