how to celebrate the autumn equinox. rituals and ideas for your equinox celebration. the autumn equinox, also called Mabon is Monday, September 22 at 2:19 pm EST. celebrating the second harvest, the autumn equinox is one of eight pagan sabbats. the autumn equinox, when day and night are equal, is fittingly the first day of Libra season. pre-order Instant Witch: The Beginner’s Guide for even more ideas and information on the wheel of the year. #autumnequinox #pagan #wheeloftheyear #beginnerwitch