Rule of 12ths and Sunlight
Wayne.B wrote in
:
On Fri, 06 Oct 2006 05:30:57 -0500, Geoff Schultz
wrote:
Does the hours of sunlight follow the rule of 12ths? I suspect that it
does, but I'm too busy to figure it out by myself and I thought that
someone might now the answer off the top of their head.
My first reaction is no, but perhaps I'm missing your intended
meaning.
The "Rule of 12ths" is commonly used to estimate tide height. How
does that relate to hours of sunlight?
Hours of sunlight depends on both latitude and time of year, largest
seasonal variation is at the poles, smallest variation near the
equator.
I just ran a spread sheet looking at the number of hours of sunlight per
month. If I apply the rule of 12ths to calculate the hours of sunlight, I
come up with a result that's within 5% of the actual result, well within my
range of error. The rule of 12ths deals with rate of change over half of a
6 hour tidal cycle and I assumed that it would also apply to daylight hours
in a 6 month cycle.
-- Geoff
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