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Subject: Re: [M]: RE: Recomputing Planet Positions/
From: Bill Nicoll
Reply To: mapug@shore.net
Date: Mon Mar 20 09:19:10 2000
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While you're here, how about checking out the
Astronomy Book
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I hadn't used my LX200 for a couple of weeks and I discovered yesterday that
the date was off by 1 day. I'm wondering if the scope didn't take into account
the fact that there was a special case in calculating whether this year is a
leap year.
The rule is: If the year can be divided by 4, it is a leap year.
Exception: If the year can be divided by 100, it is not a leap year.
Exception to the exception: If the year can be divided by 400 (like this year),
it is a leap year.
Maybe the LX200 wasn't programmed to handle the exception to the exception.
Anyway we won't have to worry about it for another 400 years.
(leap year info. from http://infoplease.lycos.com/spot/leapyear.html)
Howard C. Anderson wrote:
> Hi Ed,
>
> Yes, I believe they get calculated at power-up and yes,
> the battery backup maintains the date. That is why I never
> discovered this. I never had to change the date before.
> The date was off for some reason and when I reset it,
> I noticed it mention that it was recomputing planet positions.
> I had only set the date once before, years ago when I first
> got the scope. (I may need to replace the battery because
> I assume that is why the date was not correct.)
>
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<HTML>
I hadn't used my LX200 for a couple of weeks and I discovered yesterday
that the date was off by 1 day. I'm wondering if the scope didn't take
into account the fact that there was a special case in calculating whether
this year is a leap year.
<P>The rule is: If the year can be divided by 4, it is a leap year.
<BR>Exception: If the year can be divided by 100, it is not a leap year.
<BR>Exception to the exception: If the year can be divided by 400 (like
this year), it is a leap year.
<BR>Maybe the LX200 wasn't programmed to handle the exception to the exception.
<P>Anyway we won't have to worry about it for another 400 years.
<P>(leap year info. from <U><A HREF="http://infoplease.lycos.com/spot/leapyear.html">http://infoplease.lycos.com/spot/leapyear.html</A></U>)
<P>Howard C. Anderson wrote:
<BLOCKQUOTE TYPE=CITE>Hi Ed,
<P>Yes, I believe they get calculated at power-up and yes,
<BR>the battery backup maintains the date. That is why I never
<BR>discovered this. I never had to change the date before.
<BR>The date was off for some reason and when I reset it,
<BR>I noticed it mention that it was recomputing planet positions.
<BR>I had only set the date once before, years ago when I first
<BR>got the scope. (I may need to replace the battery because
<BR>I assume that is why the date was not correct.)
<BR> </BLOCKQUOTE>
</HTML>
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