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Calendar Jigsaws


Online retailers have started selling "Calendar Jigsaws". These comprise of two parts: a board which is a grid of squares labelled with the twelve months, dates 1 to 31 and days Monday thru Sunday; ten pentominoes (made of 5 squares each) or quadriminoes (made of 4 squares each) each a different shape. The are sufficient 'minoes' to cover the entire board except for 3 squares which should be left uncovered as "today's date". The year is a separate insert.)

So you get a new jigsaw every day:
Example: April 20 Wednesday (2022)
Example date Apr-20-Wed.
Rarely are the solutions unique.

empty board.
The 10 'minoes':
the covering shapes
which I call v p S i z l t u r s. (Note there is a big "S" and there is a little "s".

It was taking me around 10 minutes to solve some days, so I wrote a program to do all the hard work. The results are now in a spreadsheet, and Apr-20-Wed's solution is
solution Example date Apr-20-Wed.
The three exposed squares are marked with "*" or "#".

Having written version 1 of the program to successfully solve any one specific date, version 2 produced the results for all 366 days of the year and for each of the 7 days of the week. However version 3 was needed to overcome gravity. A vertical "i" piece with a space "*" below it will fall under gravity to cover the desired exposed square and leave a different one exposed at the top. Hopefully this has been successfully done.

Then I realised that the pieces had a shiny "top" side and a dull "back" side. So I modified v3 to v3b to use just the shiny sides of the minoes if possible. Shiny side only use "*" for the date markers. Mixed minoes us "#".

I offer my spreadsheet for personal use only.

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Last updated 2022-05-15
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