A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: John Simmonds
Date: 2004 Oct 18, 23:36 +1000
actually, in the military 24 hour clock .. midnight does not exist
the time advances from 23:59:59 to 00:00:01
live every day like it may be your last .. cause one day it will be
On Mon, 18 Oct 2004 08:01:38 -0300, Jim Thompson wrote:
> I am revisting my understanding of how dates change around the
> world over time (George called time/dates "slithery" -- no better
> word for it!).
> I am learning that times and dates, an arbitrary measurement tool
> applied to our spinning earth for human convenience, must have a
> set of carefully defined, fixed, arbitrary conventions to work.
> One example is using Time Zone Y on ships at sea, as agreed upon in
> 1917 at the Anglo-French Conference on Time-keeping at Sea. But I
> think it would be safe to say that another convention would be to
> avoid using the term "2400".
> Although we can think and write the term "2400", it has no
> practical meaning, is that right? As soon as the time advances
> past 23:59:59, then from a navigator's perspective the date changes
> to the next day, at time 00:00:00. The term "2400" seems to refer
> to a non-entity, a purely abstract instant of time past 2359 when
> it is midnight, but the date is still the same day.
> To resolve that conundrum, I revised the time-date conversion table
> m by changing the entries from 2400 to 0000, and shifting the date
> relationships accordingly. But the original version that used 2400
> was based on the old US Coast Guard manual, which used 2400. I do
> not know the historical context of their use of "2400", but today I
> think 0000 makes more sense.
> Am I merely catching up with the obvious?
> Jim Thompson
> Outgoing mail scanned by Norton Antivirus