More commonly known as Autumn Equinox, this Sabbat is celebrated according to what is happening in the stars.
It occurs when day and night are the same length. We have the same number of hours and minutes in both.
The Earth tilts on its axis, during its orbit around the sun. For six months, half of the planet is leaning away; and for the rest, it's leaning towards.
Naturally, there comes a moment when the shift takes place. The Earth is poised in balance, caught on the mid-point of its tilting away or towards the sun.
Known collectively as the equinoxes, this only happens twice in any given year. The other being at Ostara. The Fall Equinox is generally between September 21st and 24th.
In 2013, it occurs on September 22nd, at 20.44 GMT. This is the date on which Wiccans will be celebrating Mabon.
Of course, the fall equinox has a profound effect upon the natural world of our planet. With less sun able to shine upon our hemisphere, the weather becomes more chill. The plants begin to wither and wilting leaves cover the ground.
Whatever crops are gathered now have to sustain us through the frozen winter months. Or at least they did before supermarkets, and wax-covered preserved food aped the fresh bounty of summer all year round.
Another theme of Mabon then is Thanksgiving. A joyous homage to the fertile soil, which gave us so much food. It's a festival which marks the completion of the harvest.
It's also a time of acknowledging with friendship and respect the community around us. They brought the harvest in; and they will support us during the dark months to come.
For ourselves, it's the signal to begin winding down from the great burst of energy, which propelled us through summer. We're entering a time of reflection and repose. But first, a party.