by Aziz Inan |
Today, February 26, 2016 expressed as 2-26-2016, or simply as 2262016 is a perfect square date since 2262016 is a square number which equals 1504 x 1504 [1, 2].
Last time a perfect square date occurred was in 2009, on April Fools’ Day, because 4012009 equal the square of 2003. Year 2009 had two perfect square dates. The other was March 5, 2009 written as 3052009 which equals square of 1747.
Before 2009, the first two perfect square dates of the 21st century both occurred in 2004: February 5, 2004 expressed as 252004 (502 x 502) and September 1, 2004 expressed as 9012004 (3002 x 3002).
This year contains a total of three perfect square dates. After 2262016, the second and the third perfect square dates will occur on September 9, 2016 expressed as 992016 (996 x 996) and December 22, 2016 written as 12222016 (3496 x 3496).
After 2016, next time a perfect square date will occur will be in square year 2025 when there will be eight of them: January 9, 2025 (1092025), March 22, 2025 (3222025), April 18, 2025 (4182025), June 3, 2025 (632025), September 1, 2025 (912025), September 27, 2025 (9272025), October 9, 2025 (1092025), and October 27, 2025 (10272025).
Note that there are also perfect square dates in the day-month-year date format calendar system used by most other countries in the world, however, they mostly occur on different days compared to the month-day-year calendar system. This year, there are also three perfect square dates in the day-month-year calendar system: 16 March 2016 (16032016), 22 June 2016 (2262016), and 9 September 2016 (992016). The only perfect square date to occur this year that falls on the same day in both calendar systems is 9 September 2016 expressed as 992016.
Happy perfect square date 2262016!
Aziz Inan is an electrical engineering professor at the University of Portland. He can be reached at ainan@up.edu.
[1] A. S. Inan, "A Numerical Milestone, No Foolin'," The Beacon, Vol. 110, Issue No. 22, p. 13, University of Portland, Portland, Oregon, April 2, 2009.
http://www.upbeacon.com/2009/04/02/a-numerical-milestone-no-foolin/
[2] A. S. Inan, "Century of Squares," The Beacon, Vol. 110, Issue No. 18, p. 14, University of Portland, Portland, Oregon, February 26, 2009.
http://www.upbeacon.com/2009/03/26/century-of-squares/
