If someone mentions to me any date from the last couple of centuries I can tell them which day of the week that date fell on, and in a matter of seconds. For example, if someone says they were married on February 13th 1953, I am able to instantly tell them that day was a Friday. How am I able to do this?

The year, month and day are equal to a set of co-ordinates which lead me to a “place” that reveals the day of the week. As usual I am employing the recurrent theme of the three keys of memory, association, location and imagination – to guide me. It is beyond the scope of this article to explain the mathematics behind these codes, but trust me – they work!

I break a date into its component parts – year, month and day – and I give each part a single-digit code number, between 0 and 6. I then use these numbers to calculate the day of the week for the particular date I am seeking.

There is an alternative method to this that you can try. For a general set of memory techniques you read some awesome tips here

The Year Codes

I have devised a coding system for all the years from 1800 to 2099. We shall start with the years 1900 to 1999. First, I choose six rooms in my house. I allocate to each room a number between 0 and 6. As the garden is not a room, I call it zero. Then I place each year in a particular room (see box). To memorize these Year Codes you will be combining location with the Dominic System to imagine each year as a person in a particular room at a big party.

BEDROOM: CODE 1
1901, 1907, 1912, 1918, 1929, 1935, 1940, 1946, 1957, 1963, 1968, 1974, 1985, 1991, 1996

SPARE ROOM: CODE 2
1902, 1913, 1919, 1924, 1930, 1941, 1947, 1952, 1958, 1969, 1975, 1980, 1986, 1997

BATHROOM: CODE 3
1903, 1908, 1914, 1925, 1931, 1936, 1942, 1953, 1959, 1964, 1970, 1981, 1987, 1992, 1998

LIVING ROOM: CODE 4
1909, 1915, 1920, 1926, 1937, 1943, 1948, 1954, 1965, 1971, 1976, 1982, 1993, 1999

KITCHEN: CODE 5
1904, 1910, 1921, 1927, 1932, 1938, 1949, 1955, 1960, 1966, 1977, 1983, 1988, 1994

STUDY: CODE 6
1905, 1911, 1916, 1922, 1933, 1939, 1944, 1950, 1961, 1967, 1972, 1978, 1989, 1995

GARDEN: CODE 0
1900, 1906, 1917, 1923, 1928, 1934, 1945, 1951, 1956, 1962, 1973, 1979, 1984, 1990

The setting for your party should consist of the six rooms and a garden. It doesn’t have to be your own house, but each area must be distinct and have familiar associations, furniture, pictures, windows, and so on.

Use the Number-Shape System to remember the numbers of each room. So, imagine a golf club leaning against some book shelves in your study to help you remember the study is code 6.

The next stage is to convert each year into a person and work out where each person has been placed. If you have invested time in learning the Dominic System for the numbers 00 to 99, then you will have a list of 100 characters, and so you are already halfway there. As all the years are from the twentieth century, you need only convert the last two digits into a person, then imagine that person performing his or her action in their designated area of your home.

This will give you the code number (between 0 and 6) for the year you have been asked about. So, if someone says they were born in 1968, you imagine Stephen Hawking (68 = SH) looking through his telescope from the Bedroom, which gives you code 1.

The credit for this goes to Dominic O’Brien. I am hopeful that with a little practice you will be able to perform this memory stunt.