[tz] [Tzdist-bis] [calsify] tzdist and IANA

Luigi Rosa lists at luigirosa.com
Thu Jul 18 13:27:53 UTC 2019

Daniel Migault wrote on 18/07/2019 15:07:
>      >> Wouldn't it be nice to have an infrastructure similar to what the NTP
>      >> pool provides for time synchronization?

My two cents of an admin of hosts (mainly Windows) that travel back and forth 
thru the seven seas (namely Cruise ships).

Short version: TZ sync is a pain in the arse.

Long version.
You cannot use UTC for all the hosts because, for instance, some of them show 
information to the guests or are used to manage crew shifts (always expressed in 
ship time).

On some ships the so called "master clock" has two NTP servers: one "classic" 
UTC and the other with ship time.

We cannot use ship time NTP server because NTP clients (correctly) assume that 
NTP is about UTC, while the local time is just a "logical view" of NTP. If we 
sync Windows hosts with ship time the result is a mess (somebody said "Kerberos"?).

We concocted a simple way to sync TZ between Windows hosts.

The "TZ Server" runs the command

tzutil /g > c:\tz\tz.txt

C:\tz is shared as TZ

Every client issue the commands

tzutil /s "%TZ%"

The procedure is tested on Win2016, 2012R2 and Win10

Detailed info in my blog article:

The original is in Italian:



+--[Luigi Rosa]--

More information about the tz mailing list