AIX 6.1 & 7.1 Daylight Savings Time Issue

If you’re running IBM AIX 6.1 or 7.1 at various SP & TL levels you might want to pay attention to a potentially big timezone/DST issue that my AIX coworkers have been struggling with this week. In short, the Daylight Savings Time code doesn’t work right and causes the time to change at incorrect times. In many cases a reboot is required to make things work correctly. The support document from IBM says:

AIX systems or applications that use the POSIX time zone format may not change time properly at Daylight Savings Time start or end dates. Applications that use the AIX date command, or time functions such as localtime() and ctime(), on these systems may be affected.

You may have to reboot after installing the iFix to ensure that applications see the changes.

That’s bad news. If you run AIX I’d go take a look at support document T1013017 right away and see if you’re going to be rebooting/restarting all your stuff very soon. Hopefully you saw this already as an alert from IBM via support notice subscriptions, but there’s not much news out there so I’m hoping this public service announcement helps. Good luck!

A big thanks to my AIX ninja coworker Steve Kilcoyne for the heads-up.