[ntpwg] Comments on NTP draft -06

[M. Warner Losh]

In message: <20070628161216.GA16642 at ucolick.org>
            Steve Allen <sla at ucolick.org> writes:
: On Thu 2007-06-28T10:11:49 -0400, Danny Mayer hath writ:
: > >    LI Leap Indicator (leap): 2-bit integer warning of an impending leap
: > >    second to be inserted or deleted in the last minute of the current
: > >    month with values defined in Figure 10.
: > >
: > >            +-------+-------------------------------------------------+
: > >            | Value | Meaning                                         |
: > >            +-------+-------------------------------------------------+
: > >            | 0     | no warning                                      |
: > >            | 1     | last minute of the day has 61 seconds           |
: > >            | 2     | last minute of the day has 59 seconds           |
: > > SB> surely last minute of the last day of the month has X seconds?
: >
: > Not exactly. It's actually the last day of a specific quarter though I
: > don't think it's ever happened yet on any day but the last day of the year.

"Day" is right here, at least from historical ntp implementation point
of view.  These implementations turn on the 'today is leap second day'
in the kernel, which implements its local policy for doing that when
they see these bits set.

: No, not the quarter.  The text is right to use "month".  ITU-R TF.460
: allows for a leap second on the last day of *any* month.  That's
: another point in favor of including a reference to the official
: document.

Current ntp implementations limit this to the quarterly, and filters
them when it isn't leap day.

: Perhaps the original point was that when the LI is 0 then the last
: minute of the month should default to 60 seconds?

I think that's good, or a separate value to distinguish 

Warner