You can drag them.
See my other comment here: http://news.ycombinator.com/item?id=3458159
Swiping works, but due to its minimalistic design, I first expected it to count up when I swiped up - while it did the contrary. It behaves like the iOS slotmachine, but clearly the affordance is broken.
Does anyone know whether you can manipulate the controls by dragging, or do you really have to use those little up and down buttons?
[1] http://blog.blackwhale.at/wp-content/uploads/2011/05/UIDateP...