e-Day is an annual celebration observed on **February 7th** of each year. It is not the day for the internet or internet waste, as you may think. So are you getting a question about what this Day is all about then? You would have used the term ‘e’ in your math classes, and this celebration is just for it. Nothing weird in such a celebration as there are not so many celebration days in the calendar meant for such mathematical terms. The e-Day celebrates the mathematical constant ‘e,’ which has a value equivalent to 2.7182818. The constant e is also called Euler’s number, named after the Swiss mathematician Leonhard Euler.

– Leonhard Euler“For the sake of brevity, we will always represent this number 2.718281828459… by the letter e.”

## History of e-Day

The year when the e-Day was celebrated is unknown. There is no exact mention of the person who created such a day for the mathematical constant ‘e.’ However, there is a reason for choosing February 7th as the date for this celebration. As the first two digits of the mathematical constant ‘e’ have a value of 2.7182818, and it can be written in the month-day (m/d) format as 2/7. Hence the second month of the seventh day is the e-Day. Some other parts of the world that follow the day/month format celebrate this day on January 27 (27/1). The Euler’s constant ‘*e’* is also known as the “**Euler’s number**” after the Swiss mathematician * Leonhard Euler*. The term ‘e’ is a mathematical constant that represents the base of the natural logarithm. i.e., the unique number whose natural logarithm is equal to one and is approximately equal to 2.71828.

The mathematical constant ‘*e’* is an i**rrational number, **and a** transcendental number** that represents the idea of all continually growing systems is a scaled version of a common rate. The constant e is mostly used in logarithms, complex numbers, and exponential growth. ‘e’ is also used to calculate Continuous Compound Interest and is used in computing various aspects of Atmospheric Pressure and other natural phenomena. Euler’s constant ‘e’ is one of the most important numbers in mathematics, including 0, 1, and pi (π). The mathematical constant, e, is sometimes called Napier’s Constant. It is most often incorrectly referred to the Euler’s Constant, which is denoted by the lowercase gamma (γ) with a value of 0.57721.

The term was discovered by several mathematicians like Oughtred, Jacob Bernoulli, Huygens, Mercator, and Leibniz. However, they didn’t know its significance. It was first referenced in a book of logarithms by John Napier during the early 17th century. The first known use of e hadn’t come out until 1690 when Gottfried Leibniz used it in correspondence to the Christiaan Huygens. In that correspondence, the letter ‘b’ was used instead of ‘e.’ It wasn’t until Leonhard Euler decided to use ‘e’ to express this Euler’s constant that it finally began to become the **mathematical standard**.

## Other Celebrations on February 7

February 7 is also celebrated as

**Wave All Your Fingers at Your Neighbor Day****National Send A Card To A Friend Day****Rose Day****Extraterrestrial Culture Day**

## How to Celebrate e-Day

Celebrating the **e-Day** is quite simple. Get to know and learn more about Euler’s number, its usage, and its importance in the field of mathematics and science. You can make your child know about the history of the ‘e.’ Fill up your mouth with foods starting with the letter ‘e.’ You can eat eggs, eggplant, eggnog, or eclairs, and more. Share your e-Day celebrations pictures and your views on social media using the hashtag **#eDay**.

Thank you for reading the post. You can celebrate every day with Happydays365.org and Happy **e-Day 2023**.