For some edited dates in the CMS-Page like e.g. January 1st 2010, the date after saving shows as January 1st 2009 in the CMS, while the date in the published page shows correct (the stored value is ok).

I use the German date format “dd.MM.YY” and the time format “hh:ss” in the CMS-profile settings.

This happens for:
1st, 2nd, 3rd of Jan. 2010, but not for 4th Jan. 2010 (e.g. 01.01.10 -> 01.01.09)
1st, 2nd, of Jan. 2011, but not for 3rd Jan. 2011 (e.g. 01.01.11 -> 01.01.10)
1st of Jan. 2011, but not for 2nd Jan. 2012 (e.g. 01.01.12 -> 01.01.11)
Ok for 1st of Jan. 2013

Now I’m asking, is this an effect of some settings on my Windows-Pc or could it be related to a bug in the software? Did anyone of you experience similar problems?. I have no explanaition for this!

phpMyAdmin:
ID   Date      Author
13   2010-01-01   NULL

ArticlePage.php
class ArticlePage extends Page {
static $db = array(
'Date' => 'Date',
'Author' => 'Text'
);