Today (Apr 12) is e day.

Post Reply New Topic

It's easy to celebrate pi day, it's 3/14 since its value is 3.1415926535... . However, the Euler (or Napier) constant "e" is 2.718281828459045... and it's harder to find a day to celebrate it since February has a lot fewer days than 71. Seventy-one days after the end of January is today, April 12, or the 71st day of February.

Celebrate appropriately.

Actually, the 0.7182818284590452353602874713527th day of February is the 11th.

So 2019/2.7182818284590452353602874713527 is February 11, 2019, at about 02:41:07.399 in the morning.



Another important value derived from e is 0.63212055882855767840447622983854 = (e-1)/e = "Tau". This represents what's known as the "Exponential Decay Constant" in physics and the "Time Constant" in electrical engineering.

Happy eDay!

Please explain. The 0.718.. th day of Feb looks like it is on the first.

This can find the midpoint between date-times as well as add or subtract a constant to a date-time. MidPoint.htm

e = 2.7182818284590452353602874713527

(e - 2) = 0.7182818284590452353602874713527

If 2 is the second month, then 0.7182818284590452353602874713527 is just a little over 7/10s into the second month.

(Hmm ... you're right ... that does seem a little off ... I'll re-run the numbers ...)

The second month is 28 days long.

28 x 0.7182818284590452353602874713527 = 20.111891196853266590088049197876

So that's actually the 20th day of the 2nd month, a little over 1/9th of the way through the day, or 02:41:07.399 in the morning.

Final Answer: 2019/02/20 at 02:41:07.399 Ante-Meridian.

If you did pi day the same way, wouldn't it be around March 3? 0.1415926535897932384626433832795 * 31 .