# Square Root Day 04/04/16

Did you know that 2016 it is another Square Root Day Year?
04/04/16. (April 4, 2016)
Our next Square Root Day won’t occur until 2025, another 9 years from the posting of this blog entry. It will occur May 5, 2025. (05/05/25).
I believe it happens only 9 times in a 100 year span where we can use the last two digits of the year. See chart below. One thing we need to know is what is a square root so we can know what a square root day is.

In mathematics, a square root of a number a is a number y such that y2 = a, in other words, a number y whose square (the result of multiplying the number by itself, or y × y) is a. For example, 4 and −4 are square roots of 16 because 42 = (−4)2 = 16.1

So we need to multiply the same number by that number. So January is the first month, we will do 1. So you will do 1×1=1. So that is saying January 1. Then February is 2. 2×2=4. And so forth.

# Below is an when Square Root Day occurs:

1. 01/01/01 (January = 1×1=1) January 1, 2001
2. 02/02/04 (February = 2×2=4) February 2, 2004
3. 03/03/09 (March = 3×3=9) March 3, 2009
4. 04/04/16 (April = 4×4=16) April 4, 2016
5. 05/05/25 (May = 5×5=25) May 5, 2025
6. 06/06/36 (June = 6×6=36) June 6, 2036
7. 07/07/49 (July = 7×7=49) July 7, 2049
8. 08/08/64 (August = 8×8=64) August 8, 2064
9. 09/09/81 (September = 9×9=81) September 9, 2081

This is referring to the last two digits of the year. 2001, 2004, 2009, 2016, 2025, 2036, 2049, 2064, 2081. Then start over again 2101, 2104, 2109, 21016, 2125, 2136, 2149, 2164, 2181. And so on.

# Unusual Square Root Days

1. 10/10/100 (October = 10×10=100) October 10, 2100
2. 11/11/121 (November = 11×11=121) November 11, 2121
3. 12/12/144 (December = 12×12=144) December 12, 2144

The same applies here but it has 3 number ending instead of the two we traditionally use when calling out years. So So 2100 will have October 10; 2121 will have November 11 and then 2144 will have December 12. But we usually don’t use the last three digits of the year. But if we did, that is when those square root days would occur.
1. Wikipedia