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Re: Simple Calculation of Sunset Time required

Subject: Re: Simple Calculation of Sunset Time required
From: J Miller
Date: Wed, 20 Feb 2008 10:32:27 -0700
Newsgroups: sci.astro, sci.astro.amateur, comp.home.automation


One thing that kind of surprises me about this entire thread is that only sunset is considered!

Seems the OP wanted to use it for a Home Automation solution, and it seems to me that sunrise may also be needed! (The OP might not see it now, but it does come in handy!)

Something as simple as "turn porch light on at sunset, off at sunrise".

Therefore the table based solutions may actually require double the table space being discussed...

One other thing I didn't see (may have missed it) is if the platform/OS "knows" about DST setting, and sets it's internal clock correctly (window/linux come to mind). If that's the case, the table will need to vary each year, as the change doesn't occur on a specific J date, but on one of 7 or so.

Again, for a HA solution, I'd assume this is the case - again, something as simple as "turn on coffee maker at 6am" would be tied to "clock time" and should know about DST.

Of course, if the OP was in AZ, DST wouldn't be an issue! (now if only the rest of the US would take this "logical" approach! :) )

For HA, I would go with an math based solution vs table. You really only need three things (4 if you do DST) - Lat, long, Jdate, DST mode, and the resulting compiled code could be smaller than the table, and more accurate!

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