Oh but it does matter Frank! And in a big way.  The reason is that this dial
needs to be corrected for longitude shift (called Standard Time in ZW 2000).


If I incorrectly enter -75 for the Standard Meridian, it produces a much
different drawing with different hour lines.  If I'm not mistaken, you are
correct for those dials that show solar time (called local time in ZW 2000).
If you want a drawing of a dial with local solar time, you can enter any
value for the Standard Meridian and you get the same drawing.

(No, there will not be any analemmas.)

But thanks for asking.  I'm sure you already know all this and just asked to
make sure I wasn't making a mistake- which I often do.  But thanks to the
smart guys like you on The List, the stupidest thing that I could do would
be to not ask the question!

I had visions of them making a 65 meter sundial that was all screwed up!

Good hearing from you Frank,

thanks,

John

p.s.  I compared my ZW 2000 drawing with another one I made using Shadows
Pro which has New Delhi in its location database, and both drawings were
identical when I used -82.5 in ZW 2000.  So now I'm sure Mike and Fer are
correct and that -82.5 is correct.


-----Original Message-----
From: Frank King [mailto:[EMAIL PROTECTED] 
Sent: Friday, February 08, 2008 2:37 PM
To: John Carmichael
Cc: [email protected]; [EMAIL PROTECTED]
Subject: Re: Sundial for odd time zone

Dear John,

Your question intrigues me...

> The sundial will be located at local meridian
> (longitude) -77.0769 degrees.  If it had a
> normal time zone, the Standard Meridian would
> be -75 degrees (UT+ 5 hrs.).

True.

> But since its Time Zone is UT +5:30, then
> wouldn't its Standard Meridian be (75 + 7.5)
> = -82.5 degrees?  Is this correct?

True again.

The reason for being intrigued is that very
few sundial features depend on the longitude
or time zone.  Generally, these things matter
only when you are explaining to clients why
sundials don't indicating the same time as
that shown on their watches!

What does the software do with the information?

Are you proposing to decorate your design with
an analemma (perhaps several) that indicates
time zone time?

Best wishes

Frank


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