I've just upgraded from 3.3.2 to 3.4 and, since the first item in the change log is lots of calendar improvements, I took a look at the calendar.
Now, it's Wednesday November 15th as I write this, but unless my eyes are deceiving me, the calendar is showing it as Tuesday November 15th. The "Tuesday" column of the "Detailed month view" in the centre of the page shows the 1st, 8th, 15th, 22nd and 29th of November. (I just checked my Google Calendar, and it puts those dates under "Wednesday", so I know I'm not alone!).
The "Monthly View" smaller calendars over on the right show the same thing, except that mousing over today's date shows a 'tooltip' for "Today Wednesday 15 November" - at least that's right.
Before I raise a bug report, is anybody else seeing the same thing?