Doug Kerr
Well-known member
If we write today's date in the traditional American civil numeric format, with two digit months and days, and all four digits of the year, and without separators, it is:
11022011
This is a palindrome - a sequence of characters that is the same if read in reverse order.
I saw several news stories today that said that the occurrence of this type of "8-digit" date palindrome is a once in 10,000 year occurrence.
Of course it is no such thing.
The next such palindrome occurs on December 2, 2021:
12022021
The next one will be on October 12, 2101:
10122101
The most recent prior one was on October 2, 2001:
10022001
So I have no idea what the authors of the articles were thinking.**
Now, if we write today's date in the ISO standard numeric form* (again with no separators), we also get a palindrome:
20111102
So happy palindromic day, folks.
** Now, there is a unique property of today's date, in that specific numeric form, that can be said to be a "once in 10,000 years occurrence". That number is the product of three consecutive prime numbers (7, 11, and 13) raised to the powers 2, 3, and 2 respectively. It is said that no other palindromic date number up to CE 9999 will have that property. (I have confirmed this.)
I suspect that somebody reading an original article that included that obscure fact got confused.
There's a lot of that going around.
Best regards,
Doug
11022011
This is a palindrome - a sequence of characters that is the same if read in reverse order.
I saw several news stories today that said that the occurrence of this type of "8-digit" date palindrome is a once in 10,000 year occurrence.
Of course it is no such thing.
The next such palindrome occurs on December 2, 2021:
12022021
The next one will be on October 12, 2101:
10122101
The most recent prior one was on October 2, 2001:
10022001
So I have no idea what the authors of the articles were thinking.**
Now, if we write today's date in the ISO standard numeric form* (again with no separators), we also get a palindrome:
20111102
*Also used in Japan for "western" dates, and in Hungary
So happy palindromic day, folks.
** Now, there is a unique property of today's date, in that specific numeric form, that can be said to be a "once in 10,000 years occurrence". That number is the product of three consecutive prime numbers (7, 11, and 13) raised to the powers 2, 3, and 2 respectively. It is said that no other palindromic date number up to CE 9999 will have that property. (I have confirmed this.)
I suspect that somebody reading an original article that included that obscure fact got confused.
There's a lot of that going around.
Best regards,
Doug