Astronomy

According to the original concept there are 24 time zones. Appropriately, there is one for every hour of the day. The standard definition separates the zones by 15 degrees of longitude, with zero degrees, the prime meridian, being in the center of its zone. However, independent nations have every right to reckon time in a way that is locally useful and sensible to them. As a result there are many places that deviate from the originally defined zones, and not just by pulling an adjacent zone over to them. Some places operate on times that deviate from the Universal Time off-set by 30 or even 15 minutes, essentially creating new zones. There are 33 zones currently, taking into account all the variations.

Time in a given zone is usually given as an off-set from Coordinated Universal Time, UTC. For example, I live in the northeast US, where the off-set is UTC-5. UTC is time as reckoned since establishing atomic clocks, not the motion of the earth, as the standard. See link for more.

The point where the southern hemisphere has the least exposure to the sun is the Summer solstice.

The point where the southern hemisphere has the greatest exposure to the sun is the winter solstice.

geysers

autunmal equinox.

Mercury: None

Venus: None

Earth: Moon

Mars: Phobos

Jupiter: Ganymede

Saturn: Titan

Uranus: Titania

Neptune: Triton

*Pluto: Charon

*Pluto is not a planet but in case your are curious...

1850s

hanseatic League

prime meridian!Prime Meridian!PRIME MERIDIAN!PrImE MeRiDiAn!

Revolution

In many places including the United States, winter is defined as the period from the winter solstice to the vernal equinox, spring is defined as the period from the vernal equinox to the summer solstice, summer is defined as the period from the summer solstice to the autumnal equinox, and fall or autumn is defined as the period from the autumnal equinox to the winter solstice. In the northern hemisphere, the winter solstice is the December solstice, the vernal equinox is the March equinox, the summer solstice is the June solstice, and the autumnal equinox is the September equinox. In the southern hemisphere, the winter solstice is the June solstice, the vernal equinox is the September equinox, the summer solstice is the December solstice, and the autumnal equinox is the March equinox. The dates of the March equinox range from the 19th to the 22nd of March, the dates of the June solstice range from the 19th to the 23rd of June, the dates of the September equinox range from the 21st to the 24th of September, and the dates of the December solstice range from the 20th to the 23rd of December. Examples of the earliest season start times are in 2096, and examples of the latest season start times are in 1903.