which distro are you using and version.  if its redhat there is a great 
DST FAQ on there site: 

https://www.redhat.com/support/resources/faqs/dst/

don't forget to bounce crond - it needs to reread the timezone file upon 
service startup - unfortunately it only reads it during start up.

Joey Rockhold wrote:
> I see the word "reboot" was mentioned.  Make sure you down that drink, 
> Bob!
>
> - Joey
>
> On 3/28/07, *Justin Krejci* < jus at krytosvirus.com 
> <mailto:jus at krytosvirus.com>> wrote:
>
>     > On 3/27/07, Bob Hartmann < bob.hartmann at gmail.com
>     <mailto:bob.hartmann at gmail.com>> wrote:
>     >> Debian.
>     >> I'm not getting email from the list, btw.  I can see my posts
>     on the
>     >> archive, tho, so I appreciate your help here.
>     >
>     > You're using gmail, which doesn't handle mailing list replies
>     > particularly well.  Make sure to hit "reply-to-all" to make sure
>     your
>     > emails get sent out to the whole list, not just the person who
>     replied
>     > to your message.
>     >
>     > Anyway - I don't use debian, but I believe you can run:
>     >
>     > $ apt-get update
>     > $ apt-get install tzdata
>     >
>     > That should do it...no reboot required :-)
>     >
>     > -erik
>
>     NTP does not affect timezone settings.
>
>     To determine if your timezone data is current (at least with
>     regards to
>     the US DST change) you can run
>     zdump -v /etc/localtime | grep 2007
>
>     if you see Sun Apr 1 then you know you have old data
>     if you see Sun Mar 11 then you are current
>
>     This is a little shell script I wrote to ease updating many
>     servers of
>     mixed distros. It worked on redhat 7.3, rhel3, suse 9.2, suse 9.3 and
>     openbsd (except localtime is a symlink).
>     It assumes you're running as root.
>
>     wget ftp://elsie.nci.nih.gov/pub/tzdata2007c.tar.gz
>     mkdir tzdata
>     mv tzdata2007c.tar.gz tzdata
>     cd tzdata
>     mkdir zoneinfo.bak
>     ls -ld /etc/localtime
>     sleep 3s
>     # look to make sure localtime is not a symlink
>     ls -ld /etc/localtime > zoneinfo.bak/localtime.zdump.txt
>     zdump -v /etc/localtime | grep 2007 >>
>     zoneinfo.bak/localtime.zdump.txt
>     cp /etc/localtime /root/tzdata/zoneinfo.bak/
>     cd /usr/share/
>     tar czvf /root/tzdata/zoneinfo.bak/zoneinfo.tar.gz zoneinfo/
>     cd /root/tzdata
>     tar zxvf tzdata2007c.tar.gz
>     zic -d zoneinfo northamerica
>     cd zoneinfo/
>     cp -rf * /usr/share/zoneinfo
>     cp -f CST6CDT /etc/localtime
>     zdump -v /etc/localtime | grep 2007
>
>
>
>     Most server processes that care about time will check the
>     localtime when
>     they start and never check again during their life. You can just
>     restart
>     services but I prefer to reboot after you get patched to make sure all
>     running processes notice the change.
>
>     Java and things that depend on Java (eg recent versions of Cold
>     Fusion)
>     maintain their own timezone settings so they have OS independence.
>     Sun has
>     a great and simple tzupdate.jar file for patching all java
>     executables. It
>     worked great for me as well.
>
>
>     _______________________________________________
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>     tclug-list at mn-linux.org <mailto:tclug-list at mn-linux.org>
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>
>
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