As I write this, it is 2009-05-15 14:31, the international standard (ISO 8601) for writing date and time. It is considered big-endian in that one starts with the largest unit on the left and adds the smaller units to the left. It is certainly less confusing for sorting than writing 2:31 p.m. on May 15, 2009.
I started using this when I was working for Univac in Sweden. ISO 2014 was introduced then as the standard way for writing the date. The Swedish government and most citizens adopted it. In fact, my personnummer was 380330-9217. The 9217 is both a sequence number and the coding that I was a male foreigner. Do you see the problem that was not considered in the 1970s? Do you see what other information I gave about myself?
Anyhow, I use this date and time format unless I'm forced by a form to do otherwise. Whenever I can, all my clocks are set for 24-hour time rather than 12-hour time. I've missed an alarm too often when I forgot to set it for a.m. rather than p.m.
