[tz] posix and right directories?

[Benjamin Drung]

On Tue, 2024-03-05 at 08:11 -0600, Bill Seymour via tz wrote:
> Is there some document that explains what the posix and right subdirectories in my Linux' /usr/share/zoneinfo are all about?  Are they a regular Zoneinfo thing, or are they somehow specific to Debian Linux?
> 
> I checked theory.html and didn't see anything related to this.

The package description of tzdata-legacy should explain it:

 This package contains timezones counted in International Atomic Time with a
 -10 second offset (TAI-10s) in /usr/share/zoneinfo/right. This is the current
 IBM recommended setting of hardware clocks on IBM mainframes, which ran on
 GMT until the inception of UTC in 1972 when TAI was 10 seconds ahead of UTC.
 IBM switched to running clocks at the atomic rate and introduced the
 10-second offset in order to avoid a discontinuity.
 .
 This package also contains legacy timezone symlinks that are not following
 the current rule of using the geographical region (continent or ocean) and
 city name.
 .
 You do not need this package if you are unsure.

-- 
Benjamin Drung
Debian & Ubuntu Developer