How does the time zone info get updated?

[Rodney W. Grimes]

> 
> It gets distributed with the base packages, but I haven't figured out how to 
> keep it up to date.
> 
> The info is distributed via IANA.
>   https://www.iana.org/time-zones
> 
> It gets updated several times a year.  There were 6 during 2020.  When is 
> unpredictable, often shortly after some government passes a law to change 
> something with short notice.
> 
> I'd expect there to be some mechanism to track the updates but I haven't found 
>  it.
> 
> The tz database includes the leap-seconds.list file.  That gets updated every 
> 6 months.  I'd like to get whatever FreeBSD does for time zones to include 
> that file so ntpd can use it without having to be concerned with keeping it up 
> to date.  That only works if the zone info is kept up to date.

This only addresses the leap-seconds file, not the whole zoneinfo data:
/etc/periodic/daily/480.leapfile-ntp calls "service ntpd onefetch",
which is /etc/rc.d/ntpd, the onefetch command attempts to update
the leap-second file.

This works great if you have https support avaliable via the ca_root_nss
port, if you do not then you can fix this to fetch via http by overriding
ntp_leapfile_sources in /etc/rc.conf like so:

ntp_leapfile_sources="http://www.ietf.org/timezones/data/leap-seconds.list"
                          ^ remove s here

This is the only file you need to keep up to date to keep ntpd happy.

-- 
Rod Grimes                                                 rgrimes at freebsd.org