I've always liked Legos, so I thought this puzzle calendar was a neat item. However, the practicality of rearranging all the blocks every month...seems like one more thing to have to do. That's why I don't like those day planners where you have to write the days yourself. I like 'em pre-printed!
But if you have a little kid, it might be a fun way to teach him/her about the days of the week and calendars.