[tz] The zoneinfo file system tree structure ?

Paul Eggert eggert at cs.ucla.edu
Fri Feb 13 19:40:26 UTC 2015

J William Piggott wrote:

> Is there a reason that the old tree structure is still being used?

Sure, inertia.  Things move very slowly in the time business.

> Does it break something to have 'right' and 'posix' as sibling directories?

Well, it does mean TZ='right/America/New_York' doesn't work any more, and one 
must use TZ='../zoneinfo-leaps/America/New_York' instead.  So there is a 
compatibility issue there.

>           /usr/share/zoneinfo
>           /usr/share/posix
>           /usr/share/leaps

By default, the subdirectories are called 'zoneinfo' and 'zoneinfo-leaps', with 
'zoneinfo-posix' being a symbolic link to 'zoneinfo'.  Of course as you mention 
many distributions still do things the old way.  E.g., Debian and Fedora both 
ship multiple copies of the 'posix' directory, which obviously takes far more 
disk space than the symbolic-link approach in the tz distribution.

I don't think applications can rely on either directory structure per se.  For 
example, Solaris puts the directory in a different place, under 
/usr/share/lib/zoneinfo, and does not ship a leap-second version at all.

More information about the tz mailing list