[sf-lug] 12 am/pm controversy

[Rick Moen]

Quoting Alex Kleider (a_kleider at yahoo.com):

> Using the argument that am means ante meridian/before noon and pm
> means after noon leads to the ludicrous inescapable conclusion that it
> is impossible to designate the time we call noon, which is neither
> before or after noon; 

Well, no, not impossible to designate _at all_.  Just not possible to
designate as either "am" or "pm" -- as those mean "before noon" and
"after noon", respectively.

You could change this if you were to convince the entire world that "am"
and "pm" are henceforth to be regarded as standing for nothing in
particular but merely indicating which half of the 12-hour clock a time
lies in.  But then you'd have the further problem of getting everyone to
agree on the two edge cases -- on which matter you've already said you
differ from most other people.



> yet surely in any logical numbering system 12am and 12 pm must have
> some meaning. 

Point is, it's not just a numbering system.  The terms "am" and "pm"
have a particular semantic history, going back to the Roman Empire.
Even if they didn't, you'd still have the problem of establishing
agreement about how to designate noon and midnight.


> No one would dispute the meaning of  11:59am as being before noon the
> next sequence of that series is one minute later which is noon and
> since we've identified that sequence as "am" it follows that ...

...the next minute mark is either a boundary case between AM and PM 
(in which case it's one over which you have no agreement) or an
exception.  

Exactly as I was saying.

> One can then continue for 11:59pm and conclude ...

...that the next minute mark is either a boundary case between PM and AM
(in which case it's one over which you have no agreement) or an
exception.

As noted, those two things are "boundary cases" only if you ignore what
the terms "am" and "pm" mean.