ljs@hlhop.UUCP (11/08/83)
In response to comments on the 12 noon / 12 midnight question: If a.m. = ante meridiem (before the middle of the day) p.m. = post meridiem (after the middle of the day), then 12:00 m is noon since m = meridiem (the middle of the day) All's well so far. Now what happens if one is a navigator or astrologer, and has ephemerides calculated for UMT noon and midnight. (It's pretty important to know which is which, or you will wind up in some pretty strange places.) How do you designate them? I have both noon and midnight ephemerides, and I use N (noon) and M (midnight), because of the analogy with English words. I don't know the Latin for midnight, but it's probably something like "merinoctum", which also begins with an "m" and is no help. If there are other practical designations for this, I would like to know. Lotta Stallman BTL Short Hills
gjphw@ihuxm.UUCP (11/09/83)
This note is intended to introduce another perspective on the 12
noon/midnight melee. It attempts to place the determination of noon and
midnight within a convention that is consistent with other numbering plans
(e.g., years).
In ordinary usage, the natural numbers are used for counting. When counting
almost anything, we begin with one (1) and count through ten (10). With this
convention, ten is the last number of the first decade. The first number of
the second decade is eleven (11).
Following this convention, there would not be any year designated as zero.
The first year of any calendar (e.g., Julian) would begin with the year 1.
Note that this mades the year 2000 the last year of the twentieth century (a
year of the 1900's). The twenty-first century begins on Jan. 1, 2001.
Viewing a clock as merely a mechanism for counting the passage of time, the
first stroke of the new hour begins at the first moment that the number one
can be applied. For example, 12:00 AM is the last member of the counts used
to record the morning. Afternoon would begin at 12:01 PM. This technique
would also apply to any arbitrary precision you might wish. If you are
interested in time to the nearest second, 12:00:00 AM is the last second of
the morning while 12:00:01 PM is the first second of the afternoon.
A twenty-four hour clock has been popular with the military and the National
Bureau of Standards for many years. Still, in this system, 24:00 is the last
count of the day and 00:01 is the first minute of the next day.
If you can recall how to count, there is no ambiguity as to whether or not
to have lunch at 12:00 AM or 12:00 PM. Lunch is served at midday, which is
the last moment of the morning, which is recorded as 12:00 AM. The next
moment begins the counting for the afternoon with 12:01 PM.
--
Patrick Wyant
AT&T Bell Laboratories (Naperville, IL)
*!ihuxm!gjphwstanwyck@ihuxr.UUCP (11/10/83)
I was going to stay out of the 1200 question, but I couldn't pass up the argument by Patrick Wyant. First, Pat, Wwhen I learned to count, they told me there was a zero. And when I joined the military they told me that there was no such time as 2400, that 1 minute after 2359 was 0000. And I kept all my records that way, and I got promoted (whoops, that might bring comments on military promotions for incompetence....oh, anyway). According to the books I read, the 20th Century began at midnight, the morning of 1/1/1900. And the 21st Century will begin at midnight, the night of 12/31/1999. This all leads up to saying: your argument makes no sense to me, as it conflicts with all that I was taught. -- ________ ( ) Don Stanwyck @( o o )@ 312-979-6667 ( || ) Cornet-367-6667 ( \__/ ) ihnp4!ihuxr!stanwyck (______) Bell Labs @ Naperville, IL
minow@decvax.UUCP (Martin Minow) (11/11/83)
The proper abbreviation for noon is 12:00 M. AM means "before noon"; PM means "after noon". RSTS/E gets it right, why can't you? Martin Minow decvax!minow (Somebody once sent a SPR to Dec regarding the RSTS/E time of day -- he received a copy of the relevant page from a Naval Observatory publication.)