Re: Default date output format changed after an upgrade to buster

[John Hasler <jhasler@newsguy.com>]

rhkramer writes:
> If 12:01 pm is two minutes after 11:59 am, then 12:00 is AM.

AM means "before the meridian", that is, before the Sun crosses the
meridian[1].  PM means after the meridian.  Time is the ordering of
events.  The Sun crossing the meridian is an event which we call noon:
everything else happens either before or after it[2].  12:00 is noon
(except when it's midnight[3]) so it makes no sense to call it either AM
or PM: call it noon.  Say "12 noon" if you feel like being redundant.

It makes no sense to speak of something happening at noon: only noon
itself happens then[2]. People are going to do so anyway, though, so one
must assume that when they say "The event will occur at noon" they mean
that it will occur during the interval between noon and the first clock
tick after noon.  This makes "12:00 noon" 12:00PM.  Thus colloquially
12:00PM is in the middle of the day.



[1] Notionally.  The ancients used local solar time.

[2] This applies to any tick of your clock.

[3] Same argument applies to midnight (it's when the Sun crosses the
    other meridian), making it 12:00AM.
-- 
John Hasler 
jhasler@newsguy.com
Elmwood, WI USA