[time-nuts] am, m, pm and ?

Dave Carlson dgcarlson at sprynet.com
Sun Jul 17 23:31:36 EDT 2005

This is something that I've wondered about. I know that someone out there
will know or at least have an opinion.

It's generally agreed that time between midnight and noon is expressed as
hh:mm:ss with the "am" suffix for "ante meridian" (yes, I'm keeping this
discussion to a 12-hour clock). Also of course that times from noon to
midnight are expressed as hh:mm:ss with the "pm" suffix for "post meridian".

Also I've heard that noon is known as meridian or "m" and that the time
12:00:00 exactly could have the "m" suffix, even if this time only exists
for a brief moment, loosely speaking.

What I'm wondering is what do we call midnight, given these conventions? The
time 00:00:00 is not really pm or am, as are 11:59:59 pm and 00:00:01 am
are. Somehow saying 12:00:00 am sounds inconsistent. Is there perhaps some
archaic suffix that was or is used to denote exact midnight, just as "m" is
used to denote exact noon?

Dave Carlson

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