A. Marais was born in Germiston, South Africa, on 13 January
1964. He worked in the motion picture industry for several
years and then qualified as a computer engineer. He is also
a music composer, graphic artist and a professional
photographer. He inherited his love for number-crunching
from his mother, who is a retired mathematician.
In 1991 he read a memory-improvement book that attempted to
demonstrate how a calendar can be memorised using a mind-peg
method (linking visual imagery to numbers). The problem was
that the book was published in 1957, and the author only
covered the years 1900 - 1985. Frustrated, but intrigued,
Etienne tried to find a mathematical solution that would not
need a static memory technique to memorise each year.
Through trial and error and extensive research he developed
a "calendar key" that unlocked the mathematical
possibilities of calculating a perpetual calendar.
He coined the solution the "Marais Formula". It utilises
basic arithmetic and only requires some memory skills to
memorise the 12-digit calendar key. It is not a purely
mathematical solution, but a logical one. By practising the
method for 30 minutes a person would be able to do a mental
calculation and produce an answer that previously required
an advanced knowledge of mathematics and pages of
calculations. With regular practise, the whole calculation
can be done within 20 seconds.
formula can be applied to any year in any century, past or