This issue happens when trying to add a new event. Sometimes when I add a new event, the dates or times is not saved with the selected options. Sometimes, when the dates and times are correctly saved, the calendar portlet doesn't show the correct date.

I was thinking that the problem could be the database. I was using Postgres and the date columns of the table "contentlet" are of type "timestamp without time zone". But, then I change the database to MySql and I could also reproduce the issue.

The big problem here is: there is no way to reproduce the error by following a few steps. It occurs at random. I tried to debug in my local enviroment, and the contentlet variable seems to be fine, even after the check-in.

The error might be happening when you parsing or formatting dates. In a case where I could see this, is in the search content. After creating the event, I checked the search content portlet and the dates were also wrong in there. I debug the search, and the date that return after parsing of the lucene date '20090615170000' was 'Jun 16, 2009 01:00:00'. Sometimes this parsing works correctly.

The issue can be reproduced easily after restarting the server. After restarting the server, add a new event, go to the maintenance portlet and flush the cache. Check the calendar again. If the dates doesn't change, try to create another one. Not always happen with the first one, usually you have to add several. Try to create the events using the same dates.