The following errata for CentOS-2 have been built and uploaded to the centos mirror:
RHEA-2008:0506-05 tzdata enhancement update
Files available: tzdata-2008b-3.el2_1.noarch.rpm
More details are available from the RedHat web site at https://rhn.redhat.com/errata/rh21as-errata.html
The easy way to make sure you are up to date with all the latest patches is to run: # yum update