[K12OSN] DST Changes?

[Les Mikesell]

Jim Kronebusch wrote:
> On Thu, 15 Mar 2007 14:01:06 -0400, Jim McQuillan wrote
>> Shawn,
>>
>> I had a similar problem with a RHEL3 machine.  I installed the tzdata 
>> package, and the zdump command shown below worked, but the date still 
>> didn't show right after the DST switch over on sunday.
>>
>> I found the problem was the /etc/localtime
>>
>> On some systems its a file that contains timezone info.  On other 
>> systems it's a symlink to a file (in my case /usr/share/zoneinfo/EST5EDT).
>>
>> when you run a command that gets the current time, like the 'date' 
>> command, it looks at /etc/localtime.  if that file or link isn't 
>> correct, it'll still report the wrong time.
>>
>> So, either you need to re-point that symlink at the correct zoneinfo 
>> file, or you need to copy the correct zoneinfo file on top of it.
>>
>> save a copy of the original file tho.  And, there should be no problem 
>> doing this while the system is running.
>>
>> Jim McQuillan
>> jam at Ltsp.org
> 
> Thanks Jim, I had one server that exhibited the problem you state above.  All checks
> showed my system was ready, then when I checked the time on Monday it was off.  I'll
> take a look at the files you pointed out.

Very, very old distos used a symlink for /etc/localtime so all you had 
to do was replace the data files.  Then some versions used a copy on the 
theory that the targets on /usr might not be mounted when some programs 
start but they forgot to fix it on updates. Current versions replace the 
copy when the tzdata rpm is updated.

The way to check what it will say in the future is with a command like:
date -d "March 11"
date -d "March 12"
and note the standard/daylight time on the output.


-- 
   Les Mikesell
    les at futuresource.com