Informing the IBM Community

IBM i Daylight Saving Time Management


Spring is on its way (Halleluiah!) and next month the clocks with be springing forward an hour.  As a boy (and the youngest of my clan) I remember it was always a job given to me to go around the house and change the dozen or so clocks that we had around the place.

Nowadays the concept of having to change the time on a clock manually is almost forgotten, we seem to take it for granted that anything with half a brain will set itself.

Now it will come as no surprise to you that IBM i can set its own clock and so automatically adjust for daylight savings but by default this is not turned on; it always amazes me just how many sites out there leave it set like that and trigger the adjustment manually.

Later in this article I will walk you through checking and setting this automatic change for Daylight Saving but before that I thought it is worth also talking about a sister topic, synchronising your clocks.

Why bother Synchronising your clocks?

These days no one server does everything and almost no servers do an entire job from beginning to end without talking to another device. What does this have to do with clocks? In a word troubleshooting!

The moment something goes wrong we end up diving into logs and usually logs on more than one system and it is at this point that having the clocks synchronised is truly a blessing. That way events logged at 11:24:13 (AM) according to the clock on SERVER1 correspond to events logged at that exact time on servers 2, 3 and 4.

This may sound like a small thing but believe me when you are troubleshooting a busy environment that can generate a thousand log entries a minute, you really don’t want to have to remember that the one server is 14 seconds behind another let alone an hour.

So even if you already have got your server to adjust itself for Daily Saving Time you would still benefit from configuring NTP (Network Time Protocol) to keep your clocks locked in sync across your network. More on that next time.

Checking and Setting up Clock Changes for Daylight Saving

You can both check that you have this enabled and set it in the same place in IBM i, but like many SysAdmin functions these days it’s easier to visualise it in the GUI.  Below I’ll use the screen shots from the Navigator for i (iNav) interface but it’s pretty much the same in the Windows based IBM i Access Navigator too.

1) Open the Time Management dialogue
Do this by clicking the + to expand the Configuration and Service tree, then select Time Management



2) Open the Time Zone dialogue
Select Time Zones, then click on the Actions Button, then select Open.



3) Check and Edit your Time Zone
Check the Time Zone you current have set, if correct select it from the list (if incorrect select the correct one from the list) then click Edit



4) Open the Daylight Saving Time (DST) Dialogue
You do this by clicking on the DST tab highlighted below


5) Check DST is Enabled and Dates are correct
First check that the Enable DST is ticked
Then make sure you have the correct date and time calculation for the Start and End time for DST, the example below shows the setting we use in the UK.
Finally, check that the time shift is correct; in this case we want to shift time by 60 minutes.
Click OK to confirm.


Nice to see you

fig 8 i-UG LogoPlease come and join us at one of our 2017 User Group meetings. We will be putting on two events in March , the first in Rochdale on Thursday 2nd and the second in London on Wednesday 15th.

More details and a booking form are available at our website

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