I also reproduce the issue with Jenkins 1.440.
In /systeminfo, I have user.timezone = Europe/Paris (UTC+1).
In the build history, there is a build at "14:36:22" (in June) but in the timeline, the same build is displayed at "13:36:22" as shown in the tooltip (BAD).
And also, in the build history, there is another build at "15:21:25" (in January) and in the timeline, the same build is displayed at "15:21:25" as shown in the tooltip (GOOD).
So it seems to be an issue of daylight saving time, and in the same timeline some builds are bad and others are good.

In [1], I see that java.util.TimeZone.getDefault().getRawOffset() is used.
Perhaps, java.util.TimeZone.getDefault().getOffset(date.getTime()) should be used instead for each date, or the timezone of the dates could be changed on the server before sending the JSON of the timeline data to the client.

[1] https://github.com/jenkinsci/jenkins/blob/master/core/src/main/resources/hudson/model/BuildTimelineWidget/control.jelly#L42

Hello,

I have the same problem !
I have -1 hour of difference.

System :
Jenkins : 1.480
user.timezone : Europe/Paris

It's fixed for me for months.

System : Windows 288 r2
Jenkins 1.507
user.timezone : Europe/Paris

This seems not fixed to me, in summer time.
Reproduced with Jenkins 1.510 (local) and 1.480.3 (cloudbees).
(Windows XP, Firefox 20, Europe/Paris)

Reproduced for example, on https://javamelody.ci.cloudbees.com/job/javamelody/buildTimeTrend
I have attached a screenshot with cloudbees for April 13

oh...indeed it isn't fixed for me.
In winter time, all is good, but in summer time I have this bug too.

System : Windows 288 r2
Jenkins 1.510
user.timezone : Europe/Paris

I'm seeing the same:

System: Linux - SLES11SP1
Jenkins 1.480.3
user.timezone America/New_York