OS X time not updating

Hi Guys,

I am experiencing a weird problem which I do not find a solution for. The time in my menubar does not get updated. It only does if I click on it and the submenu expands. See images (first image no action taken, second image I clicked on the time) and notice the mismatch between the system preferences menu time display which is correct and the incorrect time display in the menu bar.

1) 17:26 vs 17:27 incorrect display

2) On click it updates correctly (only once, keeps stuck on that value than)

The problem solved itself by rebooting, but then reappeared out of nothing. It's kind of nasty if you cannot trust your time display :-/

Thanks for every help.

Tobi