All you need to create your own calendar from an old folder is of course an old folder, some screws that fit into the holes of your folder-mechanism, some piece of wood or (as I used it) a chopping board with the dimensions of 22x14cm.

Any dimension that fits your calender (mine is 13x18cm) will be fine.

Of course you can also screw the folder-mechanism directly onto a wall. In this case you won't need a piece of wood.

Step 1: Prepare the Folder-mechanism

All you need to do is grab a plier and remove the rivets that hold the folder-mechanism in place. Although they are made of metal you can remove them with some force. Be carefol not to bend the folder-mechanism too much.

Step 2: Screw the Folder-mechanism in Place

First of all grab some screws that fit through the holes you just removed the rivets from. Pay attention that they must not be longer that the thickness of your piece of wood.

Now align the folder-mechanism, mark the holes and predrill them with a slightly thinner drill compared to your screws.

Afterwards carefully screw the mechnism in place.

Step 3: Design Your Calendar

Once everything is screwed into place design your calendar.
Simply use something like word oder powerpoint to create the pages. There are plenty of templates on the internet.
My pages are 13x18cm but you can use any size you want.

Use a holepuncher to punch holes in your calendarsheets and put them into place.

Hint: You can also use it as a holder for paper to take notes on.