This is a perpetual calendar for every day of the month. It's is a redesign of a wooden version I saw years ago.
There are seven puzzle pieces. You need six to cover all dates but the actual. For every date are several solutions possible, I found at least two for every number.
If you have a plotter capable of two colors or a plotter with end of media detection you can print a version of more contrast in the numbers. Depending on the slicer program the color change should be by aproximal 60% of the total material.