The Science of the Equinox:
Two days a year, the Northern and Southern hemispheres receive the same amount of sunlight. Not only that, each receives the same amount of light as they do dark -- this is because the earth is tilted at a right angle to the sun, and the sun is directly over the equator. In Latin, the word equinox translates to "equal night." The autumn equinox takes place on or near September 21, and its spring counterpart falls around March 21. If you're in the Northern hemisphere, the days will begin getting shorter after the autumn equinox and the nights will grow longer -- in the Southern hemisphere, the reverse is true.
Global Traditions:
The idea of a harvest festival is nothing new. In fact, people have celebrated it for millennia, all around the world. In ancient Greece, Oschophoria was a festival held in the fall to celebrate the harvesting of grapes for wine. In the 1700's, the Bavarians came up with Oktoberfest, which actually begins in the last week of September, and it was a time of great feasting and merriment, still in existence today. China's Mid-Autumn festival is celebrated on the night of the Harvest Moon, and is a festival of honoring family unity.
Giving Thanks:
Although the traditional American holiday of Thanksgiving falls in November, many cultures see the second harvest time of the fall equinox as a time of giving thanks. After all, it's when you figure out how well your crops did, how fat your animals have gotten, and whether or not your family will be able to eat during the coming winter. However, by the end of November, there's not a whole lot left to harvest. Originally, the American Thanksgiving holiday was celebrated on October 3, which makes a lot more sense agriculturally.
Thanksgiving was originally celebrated on October 3. In 1863, Abraham Lincoln issued his "Thanksgiving Proclamation", which changed the date to the last Thursday in November. In 1939, Franklin Delano Roosevelent adjusted it yet again, making it the second-to-last Thursday, in the hopes of boosting post-Depression holiday sales. Unfortunately, all this did was confuse people. Two years later, Congress finalized it, saying that the fourth Thursday of November would be Thanksgiving, each year.
Symbols of the Season:
The harvest is a time of thanks, and also a time of balance -- after all, there are equal hours of daylight and darkness. While we celebrate the gifts of the earth, we also accept that the soil is dying. We have food to eat, but the crops are brown and going dormant. Warmth is behind us, cold lies ahead.
Some symbols of Mabon include:
  • Mid-autumn vegetables, like squashes and gourds
  • Apples and anything made from them, such as cider or pies
  • Seeds and seed pods
  • Baskets, symbolizing the gathering of crops
  • Sickles and scythes
  • Grapes, vines, wine
You can use any of these to decorate your home or your altar at Mabon.