How did you do the poll, though? Were they supposed to pick between two live demos, or did you just ask "should scrolling up increase or decrease the value"? In left-to-right languages, I would think most people's intuition is to scroll down to move right and scroll up to move left (with a unidirectional scroll wheel, anyway).

Hmm, when I first saw the calendar, I think oh cool, there is only one week to choose, the week above and below must be hidden, so it's nature way to navigate to previous week is to scroll up, and scroll down to see the next week.

Although it's not scroll by week but by day, but you get the idea.