Equal day & night before the nights begin to darken at 4 PM. A Pagan celebration to thank the sun and prepare for the cold to come.
This year it is on the 22 of September. I am not sure how I will be celebrating it but I suspect it will be low key like always as I rest and prepare for the 2nd week of October and all the birthdays during that week plus a dinner party to celebrate my 60th year.
The first thing I will be doing is changing the hanger on my door to the autumn one. Beyond that, I have no clue.
There are many crafts that you can do to bring autumn into your home but the celebration itself ...
Some Wiccan rituals for Mabon include building an altar with harvest fruits and vegetables, meditating on balance, gathering and feasting on apples, offering apples to the goddess, sharing food, and counting one’s blessings. Source
For a more in-depth explanation of Equinox celebrations can be found on Learn Religions. That web site contains a wealth of information on Pagan rituals and many other religions BTW if you want to learn about them.