I would love to have more information on your calendar holder too. I had plans to make one but haven't yet. I was going to do mine a little differently though, based on a paper one that I bought several years ago from the Hallmark store.
The calendar is on top and it has a pocket underneath the calendar to hold your monthly bills, etc. You could then do quilting or embroidery on the pocket and maybe a decorative border around the calendar part. I loved my paper calendar like this so much that when I couldn't find them anymore I taped a new calendar on it for two years in a row, lol! It was so cute, you couldn't tell that I had cheated, lol!!