Cloudbees Enterprise Jenkins Timezone When Machine is UTC

I did this on a Linux Red Hat Enterprise 7 machine. The problem I was having had to do with the default time zone on Linux was UTC. When I would do "time" from a command line, it would show UTC time. In my case, it was 6 hours later than the time on my phone.

Jenkins uses time in several ways and you have to make more than one change to make all of them use the correct time zone.

Note that there doesn't seem to be a way to have Jenkins figure out where the user sitting in front of a browser viewing a Jenkins screen may be located. If the server is in one time zone and the user is in another time zone, I'm hoping to have the time displayed equal the server's time zone.

Here are the places I found to check whether Jenkins is doing the time zone the way I want:

1. Go into a build job and look in the lower left margin. The time of the builds is shown there. It should be the time zone you want.
2. Go to a pipeline build job and look at the time displayed beside the flow diagrams for the builds. Again, this should be your desired time zone.
3. Go to the CJOC > Manage Jenkins > System Logs > All Jenkins Logs and notice the time of the last logged event. It should be in the desired time zone. If your server has been idle for a while, it might not contain a recent log message. Take this into account.
4. Repeat the same thing for the Client Masters. Each of them should display correct times in the log messages.
5. Go to any build job that runs at a particular time of day. On the Configure screen, there is an item for build periodically > schedule that shows one or more "cron" type strings. The 2nd column is for the hour. The message below the schedule box should show the correct time zones for the times the job was and will be run.

• A cron string "0 1 * * *" will run at 1 am every day. Check that's what it says below the schedule box.
• A cron string "H H(9-17) * * *" will run every day once per hour between 9 AM and 6 PM. The H means Jenkins gets to pick the minute value randomly.
• A cron string "@midnight" will run every night between midnight and 6 am.

1. Similarly, the times the jobs run (after they run and the time of running is in the left margin at the bottom on the build job page) should be correct in the desired time zone. You may also be able to check the time of build by looking at the dates on built artifacts--stuff like build log files and jar files and such.

1st Change

Create a file, $JENKINS_HOME/init.groovy.d/my-timezone.groovy (which Jenkins will run upon startup). Do this on the CJOC (Operations Center) machine and on any Client Masters.

System.setProperty('org.apache.commons.jelly.tags.fmt.timeZone', 'America/Chicago')

Note that you will use one of the Java timezone strings. I'm in the Central time zone of the United States. (See http://stackoverflow.com/questions/1694885/timezones-in-java)

This makes it so that Jenkins will use the defined time zone when it is formatting certain strings to contain the time of day of some event (like a log message or a build time). It sort of depends on which bit of code is doing the formatting.

2nd Change

Then you need to add a startup string to the sysconfig file for jenkins. (How do you find it? Cloudbees has help but its very confusing. https://support.cloudbees.com/hc/en-us/articles/209715698-How-to-add-Java-arguments-to-Jenkins ) Mine was in /etc/sysconfig/jenkins (or jenkins-oc)

-Duser.timezone=America/Chicago

Note that this one has to be set when Java is first starting the JVM. As the Jenkins application come up, it reads the current time zone and stores it. If we were to use the Groovy method (as above) to set this Java system property, Jenkins would have already set the default time zone for all scheduled jobs and they would all use the default time zone NOT the time zone set in a Groovy init script.

3rd Change (optional)

Though I'm not sure if it matters, I also added this to Configure > Launch Method > JVM Options on my SSH slave. It depends on which kind of slaves you have if you want to find where to put that. And I don't know how to do it with a non-SSH slave or a Windows slave.

    -Duser.timezone=America/Chicago

Finally

Restart all the Jenkins and that's it.

More Stuff

The above will get jobs building on the correct hourly schedule(s). But perhaps you have one job that needs to run on a different schedule. Perhaps a long test run that needs to occur in the middle of the Indian night when the team in India is home sleeping.

You can put the following in for the schedule using two lines:

TZ=Asia/Kolkata
H H(0-1) * * *

Which will run the build job sometime between midnight an 1 AM using India's standard time zone.

Be careful that this long running build does not interfere with the work of people in other time zones. Midnight in India is 1:30 PM here (during the US Winder).