Java and timezone issues!

David M. Karr davidmichaelkarr at
Sat Apr 18 18:19:02 UTC 2009

Knute Johnson wrote:
> Somebody posted on the other day about problems with 
> Ubuntu and Java timezones not reflecting daylight savings times 
> accurately.  I don't want to rehash that discussion but the question was 
> asked here the other day, what update messes with the /etc/localtime 
> file.  It is tzdata that came in today's updates.  It rewrites the link 
> at /etc/localtime that points to /usr/share/zoneinfo/??? to be a file. 
> This stops Java from figuring out the timezone correctly.

The two packages that got installed this morning were "tzdata" and 
"tzdata-java", one of which (or the installation process itself) changed 
/etc/localtime from a link to a hard file.  What's odd is that the 
"installed files list" for either package does not list 
"/etc/localtime".  However, I suppose if something tried to replace the 
file that "/etc/localtime" was symlinked to, the process of doing that 
might leave "/etc/localtime" as a plain copy of the original 
symlinked-to file.  The "tzdata" package had 
"/usr/share/zoneinfo/US/Pacific" in its installed files list, which is 
the file /etc/localtime is supposed to be symlinked to.

If I'm guessing correctly about what happens when a file is moved on top 
of a file that is symlinked-to, then changing /etc/localtime from a 
symlink to a plain file may be completely inadvertent.

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