- After updating tzdata on a RHEL 2.1 AS system, /etc/localtime may have to be recreated if it was a hard link or copy of an out-of-date time zone data file. See this Red Hat Knowledgebase page. e.g.,
# ln -sf /usr/share/zoneinfo/Australia/Sydney /etc/localtime
Q. The zoneinfo patch is just an update of regular files. So why do we need to reboot?
* Reboot is the only way to ensure that all applications running on the systems reread zoneinfo files.
Zoneinfo database is once read in processes/applications and is never reread. The only way to let them reread new zoneinfo files is to restart the application/processes.