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Palindromic Dates

There seems to be some considerable confusion, not to mention inaccuracy, surrounding the uniqueness or otherwise of the palindromic date which will (or did) occur at 20:02 on Wednesday 20 February, 2002 (at least, for those of us who use the UK method of date notation - dd/mm/yyyy.

The sole purpose of this page is to clarify the situation, not only for the Anglophiles, but also for our brethren on the other side of the duck pond who use the mm/dd/yyyy format. 

For the sake of both sanity and brevity, we'll consider only 4 digit years (i.e. from the year 1000 AD to 9999 AD). I think this is reasonable - apart from the fact that in his days Julius C didn't have a 24 hour clock packed in his travel supplies, I'm pretty certain they did not insert a gratuitous zero in front of their 1, 2 and 3 digit years. At the other end of the scale - beyond the year 9999 - who really gives a damn anyway. So we are considering very simply 3 groups of 4 digits each for genuine "triple palindromicity".

(For those who might wish to follow the workings for "triple palindromicity"...here they are. And if you want to see how "normal palindromicity" shapes up by comparison...here are the relevant working)

We have two scenarios - one for the US and one for the rest of the Western (Julian Calendar) world.

We (at the eastern end of the pond) have 4 Palindromic Dates:

Time Date Month Year

 Palindromicity

10:01 10 January 1001     1001 1001 1001
11:11 11  November 1111     1111 1111 1111
20:02 20  February 2002     2002 2002 2002
21:12 21  December 2112     2112 2112 2112


On the other hand, using the US system,  we find only 3 Palindromic Dates:

Time Month Date Year

 Palindromicity

10:01 October  1 1001 1001 1001 1001
11:11 November  11 1111   1111 1111 1111
12:21 December  21 1221   1221 1221 1221

I think the above is accurate, but am open to correction, suggestion and debate.

Going back to Julius C for a moment. Would anyone care to go through a similar exercise using roman numerals? To get you started - it is at the moment XV:XXVIII X V MMXIII.

Maybe some of our Jewish and Chinese friends would care to have a go at their systems too!

And for those who wish to take issue over the validity of the word "palindromicity" - don't bother - I made it up.

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