Make Perpetual Calender From Last Year's Calender

Happy New year!

Now that its a new year, will you trash that old calender?

No need, when you can make a perpetual calender from it!

Just rotate the "days disc" to align with the days!

Materials:
- Cardboard
- Tinted papers of any colors of your choice
- PVA glue
- Old pall point pen refill

Tools:
- Scissors *
- Craft knife *
- Hand drill with suitable bits to make hole wide enough for the ball point pen refill
- Hot glue gun *
- Piece of twines
- Pencils

* CAUTION : Be careful while using any sharp tools or hot glue gun.

You need the old calender that has fairly large numbers

Carefully cut the old calender using scissors

You will need four sets of days and dates from 1 to 31

You will need to find out the dimensions of circular ring

You can find out like this:
Dimensions of a date square = 1.5 x 1 inch
There are 32 such dates to be arranged in an circle, so the circle needs to accommodate 32 x 1 inch edges
so the circumference of the circle is 32
Radius of the circle is given by 2 x (pi) x (radius)
So radius of this circle comes to 32 / (2 x (pi)) = 5.1 (approx)
So my circle will have radius of 5.1 inch

Now cut out a piece of cardboard accordingly and paste tinted paper on it

I didnt have sufficiently large pair of compasses, so i needed to draw the circle using piece of twine.

Its kind of hard to explain but its given in this 'ible

I drew without the nail in center and a quarter circle in a stroke. Its kind of crude, but you can manage

Draw the circles on both the tinted paper

Now its time to paste the dates on the outer (black) paper and days on the inner ring

You dont want the perpetual calender to tear out the day you try to rotate the days!

So you need a strong pivot.

Cut three small discs out of the cardboard and drill a hole through their center

Then paste them on the cardboard of the background sheet and also on the front disc

align all the holes using a needle if needed

Pass the piece of ball point pen refill from the rear end of the rear disc. Hot glue it so that it wont fall off!

Then carefully assemble the upper disc with the lower one by passing it though the ball point pen refill

You may want to hang the calender from a nail in the wall

Bend a piece of cardboard as shown and drill a sufficiently large hole for the nail

Paste this to the rear end of the calender and you are done!

Just rotate and align the day with 1st day of the month

For example, January 2014 falls on Wednesday, so rotate the inner disc such that it aligns itself with "1"

One limitation is that the calender does not take into account the number of days in a month

Also, after making this calender i realized that it is not showing proper days for 29, 30, 31 :(

I am really trying to solve this problem and will update as soon as i find the solution