Happy Fall Equinox

Happy fall equinox - autumn is definetely here in the Northern hemisphere, the wind is colder and stronger and the temperature is getting lower and lower.
Because of the fall I added a bit fall graphic to my header, I used the brush feature in Photoshop, this brush set is not a default set but created by ploop26 on DeviantArt, you can download the set from DeviantArt .

An equinox is the moment in time (not a whole day) when the center of the Sun can be observed to be directly above the Earth’s equator, occurring around March 20 and September 22 each year.

On equinox day, the Sun rises, for every place on Earth (except at the poles), at 6:00 in the morning and sets at 18:00 in the evening local time. But these times are not exact for several reasons.

# Most places on Earth use a time zone which is not equal to the local time, differing sometimes up to an hour or more, and even two hours if daylight saving time (summer time) is included. In that case, the Sun can rise for example at 8:00 and set at 20:00, but there would still be 12 hours of daylight.
# Even those people fortunate enough to have their time zone just equal to the local time still will not see sunrise and sunset at 6:00 and 18:00, respectively. This is due to the variable speed of the Earth in its orbit, and is described as the equation of time. It has different values for the March and the September equinox (+8 and ?8 minutes respectively).
# Sunrise and sunset are commonly defined for the upper limb of the solar disk, and not for its centre. The upper limb is already up for at least one minute before the centre appears, and likewise the upper limb sets one minute later than the centre of the solar disk. Due to atmospheric refraction the Sun, when near the horizon, appears a little more than its own diameter above the position than where it is in reality. This makes sunrise more than another two minutes earlier and sunset the equal amount later. The two effects add up to almost seven minutes, making the equinox day 12h 7m long and the night only 11h 53m. In addition to that, the night includes twilight. When dawn and dusk are added to the daytime instead, the day would be almost 13 hours.
# The above numbers are only true for the tropics. For moderate latitudes this discrepancy gets larger (London, for example: 12 minutes), and close to the poles it gets very large. Up to about 100 km from both poles the Sun is up for a full 24 hours on equinox day.
# Height of the horizon on both the sunrise and sunset sides changes the day’s length. Going up into the mountains will lengthen the day, while standing in a valley with hilltops on the east and the west can shorten the day significantly. This is why settlements in east-west running valleys are more favourable (daylight-wise) than north-south running valleys.

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