HP-UX keeps only one time and that is UTC (also known as GMT or Zulu time) which is the time that the entire world uses as a reference. To accommodate humans, the world is divided into timezones, but they aren't very accurate and keep bouncing around due to political decisions.
The good news is that HP-UX can provide every timezone at the same time using a variable called TZ. Your TZ value can be seen with the command:
echo $TZ
It was set when you logged in from the value stored in /etc/TIMEZONE. This file is changed when you first install your system and pick the local timezone. This TZ value is used in conjunction with /usr/lib/tztab where the rules for dozens of different timezones (not all) are located.
So if the date command (without -u) is off by hours, don't change the time until you look at the timezone, in your case CDT which means Central Daylight Saving Timezone. If this timezone is correct for your local system, then (as root) you can change the time to match your local time. NOTE: don't change time when applications are running. To be safe, reboot into single user mode and change the time there.
Now if any users login from remote sites where they have a different timezone, they can change the TZ value in their .profile to match their local time. It will not affect the system time as the TZ value is only translating the time (from UTC) based on the rules in tztab.
NTP is the most popular (and precise) tool to keep all your servers in sync. Computer clocks will drift over time and NTP will keep your system in sync with the atomic clocks all over the Internet. Setting up NTP is easy, but finding several NTP servers depends very much on your local data center. If you have network administrators, ask them about NTP servers that already exists in your company.
Bill Hassell, sysadmin
