This is a relatively simple and inconspicuous stand for a "one-page-per-day calendar"

It is designed to accommodate the common 18x13 cm size. The spacing between the holes is 79 mm.

I suggest printing a small part of the "top" of the model firstThe negative part), so as to check whether the holes are properly aligned.

You may need to adjust the print quality settings. I tried to reduce the amount of consumables needed, but the back side didn't turn out as expected. The imitation marble consumables I used successfully masked these flaws, and the placement of the calendar won't be noticed by most people, so it worked well for me. If the back side will be visible, I recommend increasing the infill percentage and resetting the top layer options to their default values.