From New Scientist #2939, 19th October 2013 [link] [link]
Whether you write dates in the order day.month.year or month.day.year (in each case with two digits for each element), 04.04.01 represents 4 April 2001, and it is a square date because 40401 is the square of 201.
In addition to 4 April 2001, there is one other date in this century that is written in exactly the same way in each order and is also a square date.
(1) What is that date?
(2) What is the next date after today that is a square date if written in the order day.month.year?
(3) What is the next date after today that is a square date if written in the order month.day.year?
Give each answer in the form of 4 April 2001.
[enigma1771]
This Python program uses the standard Python date library to validate dates, and if you have an English locale it should output the dates in the required format. It runs in 38ms.
Solution: (1) 7 July 2056. (2) 6 May 2016. (3) 8 January 2016.
I didn’t like this one much.
A correction of a stupid error and a small speed up.