Pair that with the jQuery timepickr: http://haineault.com/media/jquery/ui-timepickr/page/

It's not bad with the year and the month view. I would have the year slide left and right, not just switch because that makes it look like nothing happened at first.

The actual date picker is a bit awkward since it's not a traditional calendar. It's a lot easier to figure out whether the 7th of the month is a Tuesday or a Wednesday by seeing which column it's in rather than what is written underneath it. That way you would have a much cleaner view as well.