[USMA:28093] RE: Calendar, date and time

[Carleton MacDonald]

When I worked at one station, an error that happened at least once a week was someone showing up at 8:00 am for the 8:20 pm departure.  “I THOUGHT it took a long time to get there,” was the usual response.   Also common was the error of showing up a day late.  “I want to leave Friday for Los Angeles.”  (departure time 12:20 am)  We book Friday, as specified.  Passenger shows up Saturday morning (late Friday night to him).  Someone else is already in the sleeping car room.  Passenger is boarding when he intended but a day later than booked.    To the public, the day does not end at midnight; it ends when they go to bed.  This is where the 24 hour clock is very helpful.  It’s pretty clear when the time goes from 2359 to 0000 that Something Happened.  Not so clear when it goes from 11:59 pm to 12:00 am.   Carleton   -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of Chimpsarecute Sent: Thursday, January 01, 2004 22:38 To: U.S. Metric Association Subject: [USMA:28091] RE: Calendar, date and time   At least the person who programmed it knew that noon is neither am nor pm and used "N" instead of "A" or "P".   By the way, who the does the American public blame if they show up for their reservation 12 h too late or 12 h too early?   Euric     ----- Original Message ----- From: Carleton MacDonald To: U.S. Metric Association Sent: Thursday, 2004-01-01 21:41 Subject: [USMA:28090] RE: Calendar, date and time   Our reservation computer at work, which still uses 12-hour time notation because the American public wants it that way, shows time as follows.   1200M – midnight 1201A – one minute after 1159A 1200N – noon 1201P – one minute after 1159P   Carleton   -----Original Message----- From: Chimpsarecute [mailto:[EMAIL PROTECTED] Sent: Thursday, January 01, 2004 19:49 To: [EMAIL PROTECTED]; U.S. Metric Association Subject: Re: [USMA:28080] RE: Calendar, date and time     ----- Original Message ----- From: Carleton MacDonald   To: U.S. Metric Association Sent: Thursday, 2004-01-01 19:07 Subject: [USMA:28080] RE: Calendar, date and time   I don’t like the idea of 24:00:00, because there is no 24:00:01.   Using 24:00:00 also means not using 00:00:00, an illogical situation because there is a 01:00:00, 02:00:00 etc.   I agree.  I mentioned that I didn't agree with that school of thought but brought it up as a way of explaining that midnight can be am or pm depending on whether midnight is meant to begin or end the day.      The changeover from 23:59:59 to 00:00:00 is simple and logical and understandable; midnight therefore belongs to the new day, not the old one.   Converted to 12-hr,   It is 12 h, not 12 hr.  There is no "r" in the symbol for hour.   this makes 12:00:00 am midnight, as it is immediately followed by 12:00:01;   Correct, but for the wrong reason.  It is AM because it is 12 hours BEFORE the meridian (before noon) on the same day.  Not because 12:00:01 am follows.  Noon (the meridian) is the fixed referance point by which the notation is derived.  Anything before the meridian on the same day is AM anything after is PM.     12:00:00 pm is noon because it is immediately followed by 12:00:01 pm.   Wrong!  Think for a moment.  The "pm" means post meridian.  Post means after in Latin.  Since noon is the meridian, it can not be after it nor  can it be before it.  There is a breakdown in logic here.  The am/pm notation can not and does not apply to noon itself.  12:00:01 is 1 s past the meridian and thus the notation pm applies. 11:59:59 is 1 s before the meridian and thus the notation am applies.  But at the meridian, neither apply.      Does this make sense to you now?   Euric     Carleton   -----Original Message----- From: Chimpsarecute [mailto:[EMAIL PROTECTED] Sent: Thursday, January 01, 2004 18:38 To: [EMAIL PROTECTED]; U.S. Metric Association Subject: Re: [USMA:28066] RE: Calendar, date and time   Technically, noon is neither pm nor am.  The pm stands for the Latin words  post meridian (after noon) and the am stands for the words ante meridian (before noon).  Since noon is the time of the meridian, then it can't be before or after, so the terms do not apply.   Midnight is also a tricky one, but since it is the start of the day, it is 12:00 am for being 12 hours before (ante) the meridian.  But some schools of thought like to place midnight as the last moment of the day.  In that context, midnight would then be 12:00 pm as it would be 12 hours past noon of the same day.   From the webpage:   http://www.cl.cam.ac.uk/~mgk25/iso-time.html   As every day both starts and ends with midnight, the two notations 00:00 and 24:00 are available to distinguish the two midnights that can be associated with one date. This means that the following two notations refer to exactly the same point in time: 1995-02-04 24:00 = 1995-02-05 00:00 In case an unambiguous representation of time is required, 00:00 is usually the preferred notation for midnight and not 24:00. Digital clocks display 00:00 and not 24:00.   The author, Markus Kuhn, makes a reference to 2 midnights in the same day.  If the two midnights were described using the 12 h clock, then one would have to be an "am" midnight and the other a "pm" midnight.  I don't agree with this concept, but since some do I thought I'd mention it.  If you don't agree with the "two midnights in one day" concept, please direct you disagreement to Mr. Kuhn and not me. Euric         ----- Original Message ----- From: "Carleton MacDonald" <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[EMAIL PROTECTED]> Sent: Thursday, 2004-01-01 13:58 Subject: [USMA:28066] RE: Calendar, date and time   > Noon is 12:00 pm in the 12-hour clock, because one minute after noon is > 12:01 pm.  It would be totally weird to go from 12:00 am to 12:01 pm. > > Midnight is 12:00 am in the 12-hour clock, because the day begins at > midnight, and one minute after midnight is 12:01 am.  Likewise, it would be > totally weird to go from 12:00 pm to 12:01 am. > > The last minute of the previous day is 2359 in the 24-hour clock and 11:59 > pm in the 12-hour clock. > > In the USA, railroads never had anything depart at noon or midnight - too > many chances for confusion and error.  It was always "12:01 am" or "12:01 > pm".  Most railroads now dispatch in the 24-hour clock for this reason; > there is no ambiguity over 0000 and 1200.  (But public railroad timetables > in the USA are still dumbed-down to the 12-hour clock for the public.) > > Although tolerated, 2400 should never be used because there is no 2401. > > Carleton > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of > Predrag Lezaic > Sent: Thursday, January 01, 2004 12:43 > To: U.S. Metric Association > Subject: [USMA:28060] RE: Calendar, date and time > > So is 12:00 Noon - 12 AM or 12 PM? I constantly have problems with using > this format on websites that use calendars. > > Predrag > > >I have the same problem as you with people who refer to 24-hour time as > >military time. However, I have difficulty believing you don't know what > >noon is. > > >