How to Become a Human Calendar

Mentally finding out the day of the week for any date is a skill you can easily learn. You don’t need to be an autistic genius – all it takes is basic memorization effort and some trivial math.
When I first learned this technique many years ago, I did it just for fun. With time, I learned to enjoy the convenience of not needing a calendar anymore. It’s far more useful than I first thought, and with just a little practice, you’ll be able to find out the days of the week much faster than when reaching for a calendar.

The Method

To find out the days of the week for any date, use the formula:

[day of week] = (yearcode + monthcode + day) mod 7

If you’re not math-inclined, this may look quite scary at first, but don’t worry: using the formula is straightforward. Let’s walk through each one of of its parts.

Month and Year Codes

The month codes are one of the formula’s most troublesome parts, since they don’t follow a clear logic. We’ll have to memorize them, but don’t worry with that just yet, as we will focus on an easy way to do this later. For now, here they are for reference:

• January: 1
• February: 4
• March: 4
• April: 0
• May: 2
• June: 5
• July: 0
• August: 3
• September: 6
• October: 1
• November: 4
• December: 6

We also need the year code, which are also apparently arbitrary. You shouldn’t also worry about memorizing them at this point. For now, here are the ones you’ll most likely use:

• 2008: 2
• 2009: 3
• 2010: 4
• 2011: 5
• 2012: 0
• 2013: 1

Days of the Week

The result is always a number from 0 to 6, and its interpretation couldn’t be any easier:

• 1: Sunday; 1st day of week
• 2: Monday; 2nd day of week, and so on.
• 3: Tuesday
• 4: Wednesday
• 5: Thursday
• 6: Friday
• 0: Saturday

The Calculation

Let me show you how the formula works with an example: December 25, 2008.
Step 1: Get the codes for month and year. According to the code tables, December is 6 and 2008 is 2.
Step 2: Apply the numbers in the formula:

1. [day of week] = (yearcode + monthcode + day) mod 7
2. [day of week] = (2 + 6 + 25) mod 7
3. [day of week] = 33 mod 7; see below if you don`t know what ‘mod’ is
4. [day of week] = 5

5 means Thursday. That’s the day of the week for December 25, 2008.

Tips for Faster Calculation

In case you’re unfamiliar with the modulo (mod) operator, all it does is give you the remainder of a division. Take, for example, 17 mod 7. If you divide 17 by 7, you get 2 and a remainder of 3. So, 17 mod 7 = 3.
Now, if you don’t like the idea of performing divisions mentally, there’s hope: you don’t really need to divide by 7 to get the number’s modulo. All you need is to cast out sevens of the number. That is: take the closest multiple of seven below your number and just take the difference between them. For example, in 17 mod 7, the closest multiple of 7 below 17 is 14. Casting 14 out of 17, there’s a leftover of 3. Therefore, 17 mod 7 = 3.
An additional tip to speed up the calculation: Instead of summing up all the three numbers and calculating the modulo thereafter, as the formula suggests, do it slightly differently: don’t wait until you have a big number to calculate its modulo. You can cast out sevens as you go. Let’s do the same calculation we did above (December 25, 2008), but casting out sevens as we go.

1. [day of week] = (2 + 6 + 25); let’s cast out sevens for 25 before we go.
2. [day of week] = (2 + 6 + 4);
3. [day of week] = (8 + 4); let’s cast out sevens for 8 before we go
4. [day of week] = (1 + 4);
5. [day of week] = 5

Although there are extra steps, you will always work with small numbers, speeding up the process.

Adjustment for Leap Years

The only caveat in the formula (and it had to have one, right?) is that there will be an adjustment when dealing with leap years: you need to subtract one from the result, for the months of January and February. The other months are calculated just as any normal year.

Memorizing the Month Codes

The math is pretty easy, but unless you memorize the codes, you won’t be able to perform the entire technique in your head. The good news is that the month codes never change, so you just need to memorize them once and reuse them over and over again. For an easy and fun way of memorizing lists, I strongly suggest the pegging memory system. We’ll use it here, so if you’re unfamiliar with it, please take a look first.
For the peg system to work, our challenge is to come up with images for the months. Here are my suggestions, based on either similarities in word pronunciation or on cultural traditions.

• January: Jacket
• February: Freeze
• March: March
• April: Bunny
• May: Flowers
• June: Dune
• July: Jungle
• August: Barbecue
• September: Scepter
• October: Doberman
• November: Turkey
• December: Santa Claus

If these images don’t make much sense to you, feel free to substitute by your own. Remember that the list doesn’t need to follow any pattern or logic; the only requirement is that each association must come easily and quickly to you.
If you did like the images I suggested, here’s a graphical list to help you visualize and memorize them as pegs:

(click for larger image)

All right, now that we have the pegs, the next step is to create fun and remarkable scenes combining the month images with our previously learned number images. Just to illustrate, let me give you a personal example on how to do that:
August. Looking at our month code table, we see the code for August is 3. Let’s associate ‘barbecue’ (for August) with ‘heart’ (for number 3): Barbecue and heart? The first thing that comes to mind is a childhood memory of the movie Indiana Jones and the Temple of Doom. I always wondered what the bad guy did with those living throbbing hearts he extracted from people in that dark ritual. No more: what about a great barbecue outside, with pulsating hearts on the grill and everybody getting drunk with kegs of Kali Ma’s blood! Childhood memories work wonders for your memory.
This technique only works if you use your own imagination, so now it’s up to you. Always remember to make it personal and fun.

Bonus: Extend the Technique for Any Year

For practical purposes, I memorize only the code for the current year. When a new year arrives and you need its code, you can find it pretty easily: find out the day for current year’s December 31th and just sum one and you’ll have the day of the week for next year’s January 1st. Now, the only variable left in the formula is the year code. Don’t forget about the adjustment for leap years when using this trick.
If, unlike myself, you want to go really wild and mentally find out the days for any year, you’ll need to grow some extra math and memorization muscles. Here’s the formula for the year code:

yearcode = (centurycode + [last two digits of year] + ([last two digits of year] div 4)) mod 7

"Div" is the operator for integer division. Just like "mod" gets the remainder of a division, "div" gets its integer quotient. For example, 17 div 7 = 2 (with a remainder of 3).
The century code follows a recurrent pattern, and can be used for any date in the Gregorian calendar:

• 1600s: 6
• 1700s: 4
• 1800s: 2
• 1900s: 0
• 2000s: 6; repeating the pattern
• 2100s: 4; 6-4-2-0 pattern goes on…

With that, you have a complete mental calendaring system. This is a handy tool that, once learned, can be used for your entire lifetime. Try it just once or twice, and you’ll see that it really isn’t as much work as it looks like.
Update: If you want the year codes automatically calculated for you, or simply want to see the math in action, I created a downloadable Excel spreadsheet (44 KB) that does exactly that.

Develop Perfect Memory With the Memory Palace Technique

The Memory Palace is one of the most powerful memory techniques I know. It’s not only effective, but also fun to use — and not hard to learn at all.
The Memory Palace has been used since ancient Rome, and is responsible for some quite incredible memory feats. Eight-time world memory champion Dominic O’Brien, for instance, was able to memorize 54 decks of cards in sequence (that’s 2808 cards), viewing each card only once. And there are countless other similar achievements attributed to people using the Memory Palace technique or variations of it. Even in fiction, there are several references to the technique. In Thomas Harris’ novel Hannibal, for example, serial killer Hannibal Lecter uses Memory Palaces to store amazingly vivid memories of years of intricate patient records (sadly, it was left off the movie).
Of course, most of us are not in Dominic’s memory championship line of business (or in Hannibal’s line of business for that matter). But still, the Memory Palace technique is amazingly effective in all kinds of endeavors, such as learning a foreign language, memorizing a presentation you’re about to deliver, preparing for exams and many others — even if all you want is to jog your memory.

The Memory Palace

The Memory Palace technique is based on the fact that we’re extremely good at remembering places we know. A ‘Memory Palace’ is a metaphor for any well-known place that you’re able to easily visualize. It can be the inside of your home, or maybe the route you take every day to work. That familiar place will be your guide to store and recall any kind of information. Let’s see how it works.

5 Steps to Use the Memory Palace Technique

1. Choose Your Palace

First and foremost, you’ll need to pick a place that you’re very familiar with. The effectiveness of the technique relies on your ability to mentally see and walk around in that place with ease. You should be able to ‘be there’ at will using your mind’s eye only.
A good first choice could be your own home, for example. Remember that the more vividly you can visualize that place’s details, the more effective your memorization will be.
Also, try to define a specific route in your palace instead of just visualize a static scene. So, instead of simply picturing your home, imagine a specific walkthrough in your home. This makes the technique much more powerful, as you’ll be able to recall items in a specific order, as we’ll see in the next step.
Here are some additional suggestions that work well as Memory Palaces, along with possible routes:

• Familiar streets in your city. Possible routes could be your drive to work, or any other sequence of streets you’re familiar with.
• A current or former school. You can imagine the pathway from the classroom to the library (or to the bar on the other side of the street, if that’s the route imprinted on your mind).
• Place of work. Imagine the path from your cubicle to the coffee machine or to your boss’s office (it shouldn’t be hard to choose).
• Scenery. Imagine walking on your neighborhood or the track you use when jogging in a local park.

2. List Distinctive Features

Now you need to pay attention to specific features in the place you chose. If you picked a walkthrough in your home, for example, the first noticeable feature would probably be the front door.
Now go on and mentally walk around your Memory Palace. After you go through the door, what’s in the first room?
Analyze the room methodically (you may define a standard procedure, such as always looking from left to right, for example). What is the next feature that catches your attention? It may be the central table in the dining room, or a picture on the wall.
Continue making mental notes of those features as you go. Each one of them will be a “memory slot” that you’ll later use to store a single piece of information.

3. Imprint the Palace on Your Mind

For the technique to work, the most important thing is to have the place or route 100% imprinted on your mind. Do whatever is necessary to really commit it to memory. If you’re a visual kind of person, you probably won’t have trouble with this. Otherwise, here are some tips that help:

• Physically walk through the route repeating out loud the distinctive features as you see them.
• Write down the selected features on a piece of paper and mentally walk through them, repeating them out loud.
• Always look at the features from the same point of view.
• Be aware that visualization is a just a skill. If you’re still having trouble doing this, you may want to develop your visualization skills first.
• When you believe you’re done, go over it one more time. It’s really important to “overlearn” your way in your Memory Palace.

Once you’re confident that the route is stamped on your mind, you’re set. Now you have your Palace, which can be used over and over again to memorize just about anything you want.

4. Associate!

Now that you’re the master of your palace, it’s time to put it to good use.
Like most memory enhancement systems, the Memory Palace technique works with the use of visual associations. The process is simple: you take a known image — called the memory peg — and combine with the element you want to memorize. For us, each memory peg is a distinctive feature of our Memory Palace.
The memory pegging technique is the same one described in the article ‘Improve Your Memory by Speaking Your Mind’s Language‘, so if you haven’t read it yet, I highly advise you to do so.
As described in that article, there’s a ‘right way’ of doing visual associations:

Make it crazy, ridiculous, offensive, unusual, extraordinary, animated, nonsensical — after all, these are the things that get remembered, aren’t they? Make the scene so unique that it could never happen in real life. The only rule is: if it’s boring, it’s wrong.

Although we can use the technique to memorize tons of information, let’s start with something very simple: using our ‘Home’ Memory Palace to memorize a groceries list. Let’s suppose the first item in that list is ‘bacon’:
Mentally transport yourself to your Memory Palace. The first feature you see in your mind is your home’s front door. Now, in a ludicrous way, visually combine ‘bacon’ with the sight of your front door. How about giant fried bacon strips flowing out from underneath the door reaching for your legs, just like zombies in those B-movies? Feel the touch of the “bacon hands” on your legs. Feel the smell of darn evil bacon. Is that remarkable enough?
Now open the door and keep walking, following the exact same route you defined before. Look at the next distinctive feature, and associate it with the second item to be memorized. Suppose the next item is ‘eggs’ and the second feature is ‘picture of mother-in-law’. Well, at this point you already know what to do… The process is always the same, so just keep mentally associating images until there are no items left to memorize.

5. Visit Your Palace

At this point, you are done memorizing the items. If you’re new to the technique, though, you’ll probably need to do a little rehearsal, repeating the journey at least once in your mind.
If you start from the same point and follow the same route, the memorized items will come to your mind instantly as you look at the journey’s selected features. Go from the beginning to the end of your route, paying attention to those features and replaying the scenes in your mind. When you get to the end of your route, turn around and walk in the opposite direction until you get to the starting point.
In the end, it’s all a matter of developing your visualization skills. The more relaxed you are, the easier it will be and the more effective your memorization will be.

Final Thoughts

What I like about the Memory Palace (and other pegging methods) is that it’s not only extremely effective, but also quite fun to learn and use.
With just a little bit of experience, the lists you memorize using the Memory Palace will stay fresh in your mind for many days, weeks or even more.
Also have in mind that you can create as many palaces as you want, and that they can be as simple or as elaborate as you wish to make them. Each of them is a “memory bank”, ready to be used to help you memorize anything, anytime.
Associating physical locations with mental concepts is the most powerful memory combination I know. Most other memory techniques (supposedly more sophisticated than the Memory Palace) are, at least in part, based on the concept of physical locations being used as memory pegs.

Remember Any Number With the Major Memory System

Did you ever want to be able to recite pi up to 22,500 decimal digits? As for me, I never felt attracted to that sort of stuff. But remembering phone numbers, passwords, PINs, birthdays and all sorts of everyday numbers — that’s something I resonate with!
Meet the Major memory system, one of the most powerful techniques around for memorizing numbers. If you think you could use a boost to your memory, or just want to jog your brain a little, here’s a great way to do it. (And yes, you’ll also be able to pull off the pi digits stunt if that’s what catches your fancy.)

How the Major Memory System Works

Our brains are notoriously poor at memorizing numbers. The problem lies in the fact that numbers are abstract concepts. Although they are represented visually by symbols, they don’t feel very real or appealing to our brains. As I explored in a previous article, our brains usually work best using lively, vibrant images. Numbers hardly qualify.
And that’s what the Major system is about: converting abstract, dull numbers into vivid, striking images. When we do that, committing these numbers to memory is a snap. Let me show you how to do it.

The Major Memory System in 3 Steps

1. Learn to Encode Numbers as Images

The heart of the Major system — and the key to convert numbers to images and vice-versa — is a 10-item mnemonic table. The table shows how to transform the digits 0-9 into corresponding sounds; which we’ll eventually use to form words. The mnemonics are easy to learn (it shouldn’t take more than 20 minutes to fully master them) and, once learned, they can be used for life. Here they are:

Digit	Sound	Memory Aid
0	s, z, soft c	z is the first letter of zero. The others have a similar sound.
1	d, t, th	d and t have one downstroke and sound similar (notice the tip of your tongue as you say them).
2	n	n has two downstrokes.
3	m	m has three downstrokes, also m looks like a 3 lying on its side.
4	r	the last letter of four, also 4 and R are almost mirror images of each other.
5	l	L is the Roman numeral for 50.
6	j, sh, soft ch, dg, zh, soft g	a script j has a lower loop like 6. These letters also have a ‘whistle-like’ sound, and 6 looks like a whistle.
7	k, hard c, hard g, q, qu	capital K contains two 7s (on their sides, back to back).
8	v, f	think of v as in a V8 motor. f sounds similar (notice how your teeth touch your lips for both).
9	b, p	p is a mirror-image 9. b sounds similar and resembles a 9 rolled around (also notice how your lip movement is the same when pronouncing these letters.)
-	vowel sounds, w, h, y	These sounds can be used anywhere without changing a word’s number value.

As an example, let’s take the (in)famous number 42.
According to the mnemonic table, the digits in the number 42 translate to r and n respectively. Now we need to form a word with r and n. We should fill the gaps between the letters using the ‘neutral’ elements (from the last row of the table: vowel sounds, w, h or y). The word rain comes naturally to me.
42 gets encoded as rain, then.
Decoding from word to number is even more straightforward. ‘Mouse’, for instance, becomes 30 (3 for m and 0 for s; vowel sounds are ignored).
The conversion process may seem a little slow and cumbersome at first, but with just a little bit of practice it becomes second-nature.
There are just a couple more notes to bear in mind:

• The conversions are strictly phonetic, that is, based on how the words sound — not how they’re spelled. If a word has double letters that account for just one sound, you count only one sound (ex: the r sound in cherry counts as only one number). By the same token, mute letters (such as the b in debt) should be ignored.
• When coming up with words, choose those that are easy to visualize. Concrete nouns — such as objects or animals — always work better than abstract nouns, adjectives or verbs.

2. Associate Images in Your Mind

Now for the fun part. We already have an image, now we’ll need a way to glue it in our minds. The way we’re going to do this is by imagining a scene, a scene that combines two images: the encoded number image along with a peg image that will be used to trigger the memory.
As an example, suppose you want to buy a light bulb, and you must remember that it must be a 30-Watt one. The two images to combine would be the image for light bulb and the encoded image for 30. Using our mnemonic table, we find that 30 translates to the letters m and s. Mouse seems a pretty good word for these letters, so we’ll go with it.
Our mission, then, is to create a mental scene combining light bulb and mouse.
The secret for this to work is to make the mental scene memorable: make it crazy, ridiculous, offensive, unusual, animated, nonsensical — in short, make it fun! (For details on how to effectively associate images, check out this article.)
Let’s see: What’s the zaniest way you can combine light bulb with mouse? I don’t know about you, but here’s what I just imagined:

“I’m in my local supermarket, in the electrical accessories aisle. As I catch one light bulb to observe it more closely… Bang! It breaks in my hand, and a giant mouse jumps out of it! The mouse runs away, squeaking frenetically. Everybody in the supermarket stops and stares at me puzzled and in absolute silence…”

Well, imagine that scene vividly in your mind and try not remembering that giant mouse next time you’re in that supermarket aisle… “30-Watt it surely is!”

3. For Large Numbers, Extend the System

“Yes, but everyone can memorize a small number such as 30,” — you say — “what about the big numbers?”
The great thing about the Major system is that you can easily combine it with just about any other memory technique, simple or advanced. That’s what makes the Major System insanely scalable and able to handle gigantic numbers.
For memorizing a small number we created a mental scene combining two images. To memorize a large number, we need to link many of those scenes together, forming a sequence.
There are many ways to do this. Many people like to create a story linking the scenes together, for example.
My favorite method, however, is to use the Memory Palace technique. In short, you use familiar places for storing memories. If you’re not acquainted with it, check it out here).
Let’s try a practical example again: an 8-digit telephone number.
The specifics on how to memorize it are a matter of personal preference, of course. The way I do it is by chunking the number in 4-digit groups, and placing each of those groups in a memory palace location.
I’ll use my in-laws phone number (slightly modified), using their home as my memory palace:
Phone number: 2417-2220
Scene 1: Associate first memory palace feature (front door) with 2417:
Using the Major system: 24 = Nero, 17 = Duck.

“As I arrive at my in-laws’ front door, I see no one but the emperor Nero himself, laughing out loud, as he is about to set the whole apartment on fire! But he has no matches or a torch in his hands: he has a blowtorch — in fact, a rubber duck-shaped blowtorch! And it quacks as it spits fire!”

Scene 2: Associate second memory palace feature (sofa) with 2220:
Using the Major system: 22 = Nun, 20 = Nose.

“As I enter their apartment is the sofa, the first thing I see is a nun chanting and jumping about on the sofa, facing backwards. When I touch her shoulder, she turns around — and it’s actually a witch! She scares the hell out of me — and guess what — she has the biggest nose ever! And yuck — that’s the biggest zit I’ve ever seen” (yes, getting disgusting is also a great way to help your memory!)

This may seem like a lot of work for a phone number, but in fact, this all happens quite fast in our minds. Recovering a number using the process above takes me no more than 4 seconds total — and I haven’t been practicing that much lately. If you practice this regularly, you’ll be able to do it much faster and with less effort.

Bonus: Gain Speed with a Word List

The previous three steps are the basic tools you need to use the Major system. If you want to make it even more powerful and efficient, one way is to use a predefined image list for the numbers you use more often.
If you use a set of predefined images for, say, all numbers from 00 to 99, you’ll greatly improve your speed when forming images, as you won’t need to imagine different words each time you trip on those numbers.
Of course, memorizing more than 100 mnemonics requires a fair amount of time and effort, but once it’s all in your long-term memory, you can use it for life. To be fair, you don’t need to memorize it (in the traditional sense of the word). Let me explain. If you just start using the mnemonics, the images will soon automatically come to you. I don’t know, but there must be something about the phonetics that makes the images manifest themselves rather easily.
Here’s a set of numbers you can use. If you don’t like these words, feel free to substitute others that are more memorable to you:

0. Sow       20. Nose     40. Rose     60. Cheese   80. Fez      00. S.O.S.   
1. Hat       21. Net      41. Road     61. Sheet    81. Fat      01. Seed     
2. Hen       22. Nun      42. Rain     62. Chain    82. Fan      02. Sun      
3. Ham       23. Nemo     43. Room     63. Jam      83. Foam     03. Sam      
4. Row       24. Nero     44. Aurora   64. Cherry   84. Fire     04. Zero     
5. Hill      25. Nail     45. Rail     65. Jello    85. File     05. Seal     
6. Shoe      26. Notch    46. Rash     66. Judge    86. Fish     06. Sash     
7. Cow       27. Neck     47. Rock     67. Chalk    87. Fog      07. Sack     
8. Ivy       28. Knife    48. Roof     68. Chef     88. Fife     08. Sofa     
9. Bee       29. Knob     49. Rope     69. Ship     89. Fib      09. Sepia    
10. Toes     30. Mouse    50. Lace     70. Gas      90. Bus                   
11. Dad      31. Mat      51. Loot     71. Cat      91. Bat                   
12. Dune     32. Moon     52. Lion     72. Can      92. Pen                   
13. Dime     33. Mummy    53. Lime     73. Comb     93. Opium                 
14. Tire     34. Mower    54. Lure     74. Car      94. Bear                  
15. Doll     35. Mule     55. Lily     75. Coal     95. Bell                  
16. Tissue   36. Match    56. Leech    76. Cage     96. Bush                  
17. Duck     37. Mug      57. Log      77. Coke     97. Book                  
18. Dove     38. Movie    58. Lava     78. Cave     98. Beef                  
19. Tape     39. Map      59. Lip      79. Cape     99. Pipe                  

What do you think?

I absolutely love using the Major system. It provides a great brain workout — and a warm feeling of relying just a bit less on technology. Even better than that is the amount of wild private imagery to have fun with!

Learn How to Start Mobile Blogging

Post from anywhere!

When you send texts to BLOGGR (256447) or photos to go@blogger.com from your mobile device they're automatically posted to your new blog.

How it works

MMS

• First send an MMS or email with the word 'REGISTER' to go@blogger.com.
• We'll reply with the address of your new mobile blog, plus a claim code.
• Post to your new mobile blog, or use the claim code to link your phone to a different blog.
• To unlink your device from Blogger, send an MMS or email with word 'UNREGISTER' to go@blogger.com.
• Standard message & data rates apply.

or use SMS

• First send an SMS with the word 'REGISTER' to BLOGGR (256447).
• We'll reply with the address of your new mobile blog, plus a claim code.
• Post to your new mobile blog, or use the claim code to link your phone to a different blog.
• To opt out of receiving SMS messages to your phone, text STOP to BLOGGR (256447)
• To get help from your mobile device, text HELP to BLOGGR (256447)
• To unlink your device from Blogger, text UNREGISTER to BLOGGR (256447).
• Sending text messages to BLOGGR (256447) is currently available for US phone numbers only.
• Standard message & data rates apply.

Devices and more

Blogger Mobile works with any device that can send texts via SMS, or email via MMS. Google does not charge for this service. Standard message & data rates apply.
Blogger Mobile is also built into some Sony Ericsson cameraphones, so you can post to your blog with just a few clicks.

For more about mobile blogging, see: How does Blogger Mobile work?
iPhone users: Phones without MMS can still post to Blogger with SMS, or via email with Mail2Blogger.