My Jenkins system clock is set to GMT. In order to display build timestamps using local time, I invoke Jenkins like this: 'java -Dorg.apache.commons.jelly.tags.fmt.timeZone=America/Los_Angeles -jar jenkins.war'

In all my regular builds, and at the bottom of every page in the 'Page generated' field, I see the local time. But in the dashboard portlet view, I see the system/GMT time. See attachment for an example - that build was run at 11:53am local time.