A perpetual calendar is a calendar valid for many years, usually designed to allow the calculation of the day of the week for a given date in the future. You can easily make one yourself of different materials and in various colors. Erase board is a simple base for such a calendar or a planner; a vintage postcard calendar journal is a charming piece for those who love style. An event calendar is very comfortable in using and allows you not to forget of the important dates. A perpetual desk calendar is great for a working place and done right in the minimalist style. Look for some more ideas below and get inspired!