The 12-cent Perpetual Calendar

You don't need a new calendar for the new year, if you've got 12 cents and an understanding of binary numbers! Evil Mad Scientist Laboratories posted instructions for making your own perpetual calendar.

It's Wednesday, the fourth day of the week. The binary number for 4 is 100. We use "heads" for 1 and "tails" for 0. So the left hand column has (top to bottom) heads-tails-tails = 100 binary = 4th day of week = Wednesday. (If you don't already speak binary, no biggie. Start here or here and join us in a minute.)

It's December, month 12, and 12 in binary is 1100, so the middle column is heads-heads-tails-tails.

Finally, the last column is all heads, since it's December 31, and 31 decimal = 11111 binary.

Got that? Me neither. Link