http://www.philly.com/philly/news/Day_for_number_geeks_11-12-13.htmlPeter Mucha, Philly.com

Last updated: Tuesday, November 12, 2013, 7:26 AM

Today's a day for recognizing order amid the onslaught of chaos, or for having a memorable wedding date.

It's 11-12-13.

And if you believe in making moments count, this morning offered two special ones as well: 8:09:10 11-12-13, taking this down to the second, and 9:10 11-12-13, which will last for a whole minute.

Last year had not only 10-11-12 but 12-12-12, a triple that won't happen again till the first day of the next century.

The fact that there won't be a 13-13-13 shows we're near the end of a period with frequent numerologically curious date patterns, because no longer can the year match the month.

Next year will have the last sequential date, 12-13-14, till 01-02-03. (Go by European notation, putting the date first, and Dec. 11 -- also written 11-12-13 -- will mark the end of that sort of sequential pattern this century.)

Oh, there will still be quadruples every 11 years (2-2-22 is next), and yearly doubles (1-3-13), but they lack the proper symmetry factor.

A couple of extra-special Pi Days are coming, though, where the year comes into play. They are 3-14-15 - matching the mathematical constant's first five digits - and 3-14-16, which is closer to its actual value of 3.14159 etc.

A yearly series of countdowns by ones ended with 12-11-10, and palindrome fans, who had their heyday from 11-1-11 to 11-22-11 a couple of Novembers ago, will have to settle for the strained likes of 4-1-14 or 02-11-20 until next century.

And after next year, you'll have to wait until 1:02 03-04-05 to again include hours and minutes.

Patterns can always be found, of course.

11-22-33 will actually be the first such triple double date this century.

Counting by odds or evens suggests the likes of 5:07:09 on 11-13-15.

It's a Friday the 13th, by the way.