The MOMA Perpetual Desk Calendar, designed in 1998 by Gideon Dagan, is functional art for your home or office. Though it might appear as a minimalist sculpture of a silver ring bisected by a black bar with two mysterious smaller orbs, it is, in fact, the only calendar you’ll ever need. The premise of the object is simple, move the magnetic silver orb along the black bar to indicate the day, and the seemingly floating black orb to indicate the month. From a distance, perhaps on a shelf, it returns to its status as art, while up close it lets you know your place in the year. Simple, and elegant.