Nope, the arrows on the toolbar are left/right so it seems more logical to swipe left/right.
I get where you are coming from though, but people are more used to left/right with electronic calendars, you aren't using a physical calendar here.
Not to mention it would make no sense for the gesture to be up/down when in "Day" view or whatever. It also wouldn't make any sense to have different gestures for each view.