[USMA:28080] RE: Calendar, date and time

[Carleton MacDonald]

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.   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, this makes 12:00:00 am midnight, as it is immediately followed by 12:00:01; 12:00:00 pm is noon because it is immediately followed by 12:00:01 pm.   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. > > >