perpetual calendar

MORGAN: I was getting the urge to look for a non-paper calendar and stumbled upon this great design! A perfect calendar to use year after year, you simply move the two magnetic balls to mark the date and month. { Made for the Museum of Modeern Art using injection molded plastic and magnets, it can be wall mounted or used on a desktop. Gideon Dagan 1998.}
found at thedailyplanner.com