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## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

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Re: Is the date ever the same globally?
From: Jim Thompson
Date: 2004 Oct 15, 20:33 -0300

```I reconcile the conundrum you pose by noting that Time Zone Y (ZD +12) is a
7.5 degree sliver of the world that arbitrarily is in the previous day, when
all the rest of the world is in the same day as Greenwich, at GMT 1200.  In
other words, at GMT 1200 it is 2400 in Y (ZD +12), but 0000 in M (ZD -12).
That preserves the notion that we lose a day going east across the Date
Line.  Then at 2401 the time in Y becomes 0001, and the date changes to the
same day as Greenwich, but the time in M becomes 0001 the next day.
Splitting the 15 degree zone around the Date Line into Y and M allows us to
have different dates on either side of the Date Line at all hours, while
allowing the time to be the same in both Y and M.  All this is why I think
that the statement, "at the instant of GMT 1200, the date is the same all
over the world" is wrong.

But I will be interested in hearing more from Luis about his diagram.

Jim Thompson
jim2{at}jimthompson.net
www.jimthompson.net
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-----------------------------------------

> -----Original Message-----
> [mailto:NAVIGATION-L{at}LISTSERV.WEBKAHUNA.COM]On Behalf Of Jared Sherman
> Sent: Friday, October 15, 2004 7:56 PM
> Subject: Re: Is the date ever the same globally?
>
>
> An interesting diagram. I notice that it lacks an "2400" position on it
> though. Surely, at the instant of 1200GMT there are simultaneous
> instants of
> 0000 and 2400 though. And we are taught that 0000 is the start of
> a new day,
> while 2400 is the end of the old day--even if they are the same instant.
>
> How do you reconcile this, then?
>
>

```
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