I cant be the only person who has spent years fighting with wall calendars. The holes in them are often so close to the edge that as soon as you hang them on a nail in the wall, the paper rips right by the hole. Over the years I have cussed repeatedly, applied paper clips, tape, and cussed more, and even trashed a few otherwise usable calendars.
Worse yet, when they are finally hanging, if you have enough humidity in the house, like from bathing or using a humidifier, the calendar curls. Arrrgggghhhhhhhhh.....
I just happened to be hanging my calendar when the hole ripped. I was also eating some potato chips, which I had sealed the bag with some of those spring loaded plastic clip devices you can buy almost anywhere to keep bags sealed. I think they are sold as "power clips". I grabbed one of them, and clipped the calendar in it. PROBLEM SOLVED, except there was no hole in the clip to hang it on the wall. A few seconds later with a 1/4" drill bit and my cordless drill, and I had a hole in the clip's handle. Making sure the head of my nail was not over 1/4", I slipped the clip on the nail, and the calendar is hanging properly, and will be easy to change next month.
The clip is about 4" wide, so the calendar should not curl. If it does, I'll look for a wider clip, or could probably glue a thin strip of aluminum to it, so it covers the whole width of the calendar.
I've been fighting with calendars for over 60 years, always wishing there would be a better way...... NOT NO MORE!
PS. I bought a three pack of those clips at the "Dollar Tree" store for a dollar.... Guess I'll have to buy a few more packs now!!!!