Ink Calendar
This is a brilliantly simple design. All the days are represented on the calendar as white numbers made up of a material that wicks moisture, and all the numbers are connected together. A bottle of ink sits on a shelf on the calendar and a strip of the material that makes up the numbers is placed in the ink bottle. The numbers are at such a specific size that it takes up a complete day to wick up the ink to fill in each number.
Just make sure you start each month at the correct time.
