sunshine stuff

Starting in 2007, Daylight Savings Time in the U.S. will start earlier and end later. We will have about 3 more weeks of DST. Our start and end dates still won't match up with Europe's.

From Wiki... "Clocks will be set ahead one hour on the second Sunday of March instead of the current first Sunday of April. Clocks will be set back one hour on the first Sunday in November, rather than the last Sunday of October. ... This will affect accuracy of electronic clocks that had pre-programmed dates for adjusting to daylight saving time. The date for the end of daylight saving time has the effect of increasing evening light on Halloween (October 31)."

..

My compass doesn't seem to consistently point in the same direction for North. Sigh. How can I use my compass, when I can't even be sure it's pointing in the right direction?


Columbia, SC data
(latitude 34 degrees north, longitude ~81 degrees west)

- Magnetic North is 6 degrees 40' west of geographic North

- On the summer solstice, sunrise azimuth is at ~ 61 degrees, and sunset is at ~298 degrees.
- On the winter solstice, sunrise azimuth is at ~118 degrees, and sunset is at ~241 degrees.

Ie., the sunrise angle varies between 0 and ~29 degrees north and south of Due East
and the sunset angle varies between 0 and ~29 degrees north and south of Due West.

- The sun's highest altitude in the sky is...
on the summer solstice at 80 degrees,
on the equinox at 56 degrees,
and on the winter solstice at 32 degrees.

- In the summer, earlist sunrise is at 6:12am and latest sunset is at 8:40pm (Daylight Savings Time).
- In the winter, latest sunrise is at 7:30 am and earliest sunset is at 5:15pm (Standard Time).