On 7 February it is e Day, which celebrates Euler’s number. Although named after the first user of the letter – Euler, e as a concept was actually discovered by Jacob Bernoulli, 22 years before Euler was born.
e is a transcendental number with an infinite decimal expansion, like π. e is the base of the Natural Logarithm, and heavily involved in exponential growth and complex numbers.
e Day is celebrated on the 7th of February, which is 2/7 in the MM/DD/YY Date system that is common in countries like America, this is e rounded to the nearest tenth, which is the only way that e could be rounded into this date system.
e Day is used to appreciate the significance of e, especially in Calculus and Complex Analysis. Many people celebrate e by learning more about e, and eating food that begins with the letter e, like eggs and eclairs.