Memorizing the calendar will allow you to amaze and impress your family and friends with seemingly impossible mental feats. It’s actually quite easy to do with a little practice.
For each year that you want to memorize, all you need to do is remember a twelve-digit number. For the year 2005, that number is 26-63-15-37-42-64. Each digit in that number represents the first Sunday of the month. For example, the first Sunday in January is the 2nd. The first Sunday of February is the 6th, and so on.
Now, suppose someone asks you what day Christmas falls on in 2005. First, you retrieve the 12th digit of your secret number; this is 4. Now you know that the first Sunday is on the 4th. You also know that Christmas is 21 days later. Since a week has 7 days, you know that Christmas is exactly 3 weeks ahead and thus also falls on a Sunday. Let’s try a harder example: July 21. The secret number for July is 3. There are 18 days between the 3rd and the 21st. That’s 2 weeks and 4 days. Since adding a week takes you back to the same day, we only need to add 4 days to Sunday, which is Thursday. Tada!
All you need is an old calendar to construct the secret 12-digit number for that year. Now, you just need to memorize those 12 numbers. This is what the Phonetic Mnemonic System is great at. Using this system, the secret number listed above can be represented as “Notch, Gym, Tail, Hammock, Horn, Chair”, which you could easily link together using the Link System. With a little practice, you could memorize several years and be able to calculate any date for those years with only a few seconds of thought.