I am way into advent calendars right now and I made one for my kids' birthday, I put the calendar on sheet metal so that everything is magnetic and I can change everything each month. I made a little place for others in the family to write special things about that person during the month of their birthday. On the blue strip I have each month of the kids' birthday and will but the month up when it's their birthday month. I also made each person name and the month and day of their birthday and will change that out each time.
A closer look of the days, each day is magnetic. I had so much fun with this and love how it turned out.