Keeping Time

Keeping time on IRIX is an easy to do, but less-than well documented thing. This article aims to educate users on the best ways to synchronize, keep time and manage it appropriately.

UNIX Date and Time

IRIX, like all System V UNIX releases, centers around the date command for timekeeping purposes. Date can set the time, tell the time, and format time in various fashions, down to the second (a limitation of the UNIX time() syscall). Examples can be found here, not all are directly supported by IRIX.

Automating Time Synchronization

Historically, IRIX used timeslave and timed to synchronize time. Examples of timeslave and timed can be found at those links.

Because of security concerns and how they are unmaintained, there are better alternatives included with IRIX. The simplest is ntpdate which can simply be invoked with ntpdate us.pool.ntp.org, substituting a proper pool server in the user's home country for the us one. This can be placed into the crontab to run at a regular interval.

ntpd is also available in SGI Freeware, Nekoware, and many other distributions for synchronizing the time. All that needs to be done is set a list of servers in /etc/ntpd.conf (Warning: not all distributions will put ntpd here!!! Consult the distribution's maintainers if it's unclear where to set it) and then /etc/init.d/ntp (or the appropriate source for the initscript) needs to be started for the daemon to run. chkconfig is used to enable the daemon.

Timezone

Setting the timezone in IRIX is relatively easy. The file /etc/TIMEZONE (This is case sensitive) is read at boot to set the system timezone. This is a text file and various strings can be inserted. "TZ=:Europe/Berlin" is a valid string, as is "TZ=:EST5EDT" or something similar. The nuances of this are in the https://nixdoc.net/man-pages/IRIX/man5/environ.5.htmlenviron manpage.