Description Perpetual Calendar (Red / Black) is a unique design object made for a lifetime. Set the date and month by simply moving the two magnetic balls. First designed for MoMA in 1998 this smaller version of the Perpetual Calendar was introduced in 2008 to commemorate the 10th anniversary of its original design. To use simply insert the stand to place the calendar on a desk and move the magnetic balls manually to mark the date and month. Designer Gideon Dagan has developed numerous consumer and commercial products including hand-held computers and electronic instruments. His innovative designs have been exhibited in museums around the world.