If we publish a new Announcement with displayImmediately checked, it will be displayed in the portlet with some delay. Refreshing the page might be necessary.
This behavior is caused by
SOS-1975. It was an intentional change to add an extra minute to the display date so this way email notifications can be sent.
There was an API change in 6.1.30, which could be used to fix this issue, but that is not available in 6.1.20 so the decision was that adding an extra minute is an acceptable solution.