On a second look, I suppose all the of results I found earlier wouldn't quite accomplish what you're looking for. Sorry about that!
However, I did find some other examples that you might like:
Create a flipping calendar/number element in #powerpoint for your #articulate #elearning courses. (With PowerPoint, so may not be the one you're looking for)
Flipbook Engage Interaction (another Engage tutorial, but I really like the page turn effect - you could insert the interaction into Storyline)
I couldn't find anything specific to calendars, though. Do you remember if it was a forum post, or a tutorial?