**From New Scientist #2737, 5th December 2009** [link]

4 April 2001 was the first doubly square date of the century because whether written in the order *day.month.year* or in the order *month.day.year* (in each instance with two digits for each element) it comes out as 04.04.01, and 40401 is 201^{2}.

Still with two digits for each element, there are some doubly square dates for which the square that comes from the order *day.month.year* is not the same as the square that comes from the order *month.day.year*. This is the case for each of the next two doubly square dates after 4 April 2001. What are those two dates (in the same form as 4 April 2001)?

[enigma1574]

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The following Python program runs in 50ms.

Solution:The dates are 12 April 2009 and 4 December 2009.