I made one of these several years ago for my sister who is a master seamstress. I filled it with all sewing notions like safety pins, buttons, thread, zippers, little scissors etc. I am not sure which was more fun making the calendar or filling it. (I felt like I was on a scavenger hunt looking for things that would fit to match the sewing theme.)
These two that I made are for two special little girls in my life. It was so fun filling these too with rings, lip gloss, hair things etc. I even found two tone lucky rabbit feet for each calendar. (They are going to freak when they open those doors.)
Here is a close up of one.