Never forget a birthday again! This perpetual birthday calendar enables you to note down all the important dates in the year, such as birthdays and anniversaries, and it will then serve to remind you of all those important 'must not forget' events in your life.
You get a month per page, and each month is accompanied by a black and white optical illusion. Hang the calendar somewhere where you will notice it (the kitchen maybe?) and never forget a birthday again.
Each month simply numbers the days 1,2 3, etc, so you can use the calendar for ever. However, although it will know that someone's birthday is on March 11th, it will not know what day of the week that is in any particular year, just that the birthday falls on the 11th of the month.