We have already covered some of the most distinctive calendars in the blog, but the “Ring Calendar” by designer Sebastian Bergne is unique in its own way. Developed for Spunique, the $74 (£45) wall calendar requires physical interaction on part of the user to keep informed about each passing day and month. Featuring a white melamine surface, laser cut from MDF sheet, the perpetual calendar integrates different rings, which need to be rotated to reflect the correct date, day and month on the wall.