Wrong milestone dates on project page

Hey guys,
I am succesfully using project pier but I've got a little problem.
When I set up a Milestone e.g. due to 10th june the date on the project page (Upcoming milestones (in next 30 days))is always +1 day but the days left are still right though.

It's very strange. My accounts timezone and my companies timezone are both GMT +1 Berlin.

I am using version 0.8.0.2 with the go_collab_monochrome theme. I am running project pier on my local server so the server should also have timezone GMT+1.

Maybe it has nothing to do with the timezones but what else?

I hope someone can help me.

regards cyph