- 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updating tzdata on a RHEL 2.1 AS system, /etc/localtime may have to be recreated if it was a hard link or copy of an out-of-date time zone data file.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.