The going theory is that the PS3 is storing some form of date in GMT, then modifying that to get whatever you see in the on-screen clock. That modification process seems to be fine--the system can take 2/28/2010, 9PM GMT, add four hours, and get 3/1/2010, 1AM random time zone.
What's apparently effed, as speculation goes, is when the internal GMT-tracking rolls over to 3/1. It's either not rolling, or rolling to 2/29, at which point a system tries to add/subtract from 2/29, which it can't do because the front-end calendar doesn't have a 2/29/2010, and shit explodes. Seemed to happen around 4PM PDT, which I think is 12AM GMT, so.
And the PS3 launched in 2006; it's hit 4 2/28s so far. 2007 and 2009 were odd-numbered years; 2008 was an even, and a leap year. 2010 is the first even non-leap-year the system's been around for. If some sort of base-level math is choking on itself, it may have ruled out the odd 2007 and 2009 successfully, but is convinced the even 2010 is a leap year (this part I'm less sure of, but is why leap year could theoretically come into play at some point.)