Refraction of sunlight through Earth's atmosphere extends daylight by
several minutes. Without an atmosphere, there would be exactly 12 hours
only on the equinoxes and at the equator.

Go here http://aa.usno.navy.mil/data/docs/RS_OneYear.html and set the
coordinates to 0 degrees latitude to see that each day is longer than 12
hours by about 7 minutes year-round at the equator.

Here at 36deg 41' N, March 16 is the first 12 hour day. March 20 is 12
hours, 7 minutes -- just like at the equator on the same day.



Iris Cohen wrote:

Really? How did you accomplish that with the Equinox a week away?
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)