Dealing With Daylight Savings Time

It is coming up on the end of daylight savings time and that means questions; specifically how to change the time zone, does ntpd need to be stopped and restarted when the time zone changes and if ntpd is running will it change the time zone automagically.

Let’s take the last two questions first since they are the easiest. You do not need to stop and restart ntpd when the time zone changes and ntpd will not change the time zone for you. The time server communicates the time to ntpd in UTC (Coordinated Universal Time). This is a time zone / daylight savings time neutral value. Setting a time zone adjusts what time is displayed not what time it is.

The OpenVOS command to set the time zone is “set_default_time_zone“. Assuming you live in an area using one of the 58 time zone abbreviations that OpenVOS knows about, you can just provide the time zone abbreviation. For example: “set_default_time_zone mst” changes the time zone to mountain standard time. You can find the table of known time zone abbreviations at http://stratadoc.stratus.com/vos/17.0.1/r281-08/wwhelp/wwhimpl/js/html/wwhelp.htm?context=r281-08&file=ch15r281-08ak.html.

If you live in an area with a time zone unknown to OpenVOS you can use the difference argument to define the offset from UTC. For example, if you lived in the “noa” time zone, with a daylight savings time offset of -360, you could move to noa standard time with the command “set_default_time_zone noa -420” and back to daylight in 6 months with “set_default_time_zone noa -360“

Remember, OpenVOS does not automagically move between daylight savings time and standard time. You must either do it manually or run a command macro in a batch job to do it. This year the change will happen (in the United States) at 2:00 AM on November 1st.

One final point, don’t forget all the devices that may be attached to the module.

To change the ftScalable controllers login into the home page at http://10.X.1.20/ and select MANAGE in the far left frame, followed by “GENERAL CONFIG” and then “set date/time”. Remember to change the other controllers at 10.X.1.21, 10.X.1.22 and 10.X.1.23 as well.

To change the Emulex switches login into the home page at http://10.X.1.10/  (and 10.X.1.11) and select “Date and Time” in the far left frame. There is no time zone information; you have to adjust the actual time.

For the Dell switches login into the home page at http://10.X.1.75/ and select “System” in the far left frame, followed by “General” and then “Time Synchronization”. Since the switches are stacked you only have to make one change.