RE: Military time (whoops!)

[Carl Distefano cld@xxxxxxxx]

Reply to note from "Brian Henderson"  Sat, 17
Jun 2006 08:56:59 -0700

> The day starts at 00:00:01. Or it SHOULD.

Patently untrue! 00:00:00.5, or 00:00:00.0000000000000000000000000001
for that matter, belongs to today, not yesterday.

Everyone agrees that the day has 24 hours, which can be subdivided
infinitesimally. Midnight, the dividing line, has no duration.
Whether it belongs to today or yesterday is of no consequence to the
_measurement_ of time; the day still has 24 hours. Whether midnight
is part of yesterday or today is a matter of convention or definition
-- choose one and stick with it. Universal Military Time is clear and
unambiguous: the new day starts at 0000 hours (inclusive);
2359.999999999999999999999999... belongs to the day before. One does
occasionally see "2400 hours", and the meaning is usually clear, but
it is wrong. The official usage is 0000.

The UTC convention for specifying atomic time is even clearer, because
it includes the date and time to six decimal places (millionths of a
second). Today, June 17, 2006, started at 2006-06-17T00:00:00.000000.
To say that June 17, 2006 started at 2006-06-16T24:00:00.000000 is
possible, but unhelpful. You might as well say June 17 started at
2006-06-15T:48:00:00.000000. A time specification needs to be self-
evident; you shouldn't have to "do the math". And that's what "24:00"
forces you to do.

--
Carl Distefano
cld@xxxxxxxx