This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Autumn Months gathers the three months the Gregorian calendar's customary northern hemisphere convention places in autumn, September, October and November. Each member's own season correspondence fact names that convention explicitly and also notes the same three months fall in spring south of the equator, so the grouping's own edge is built into its members rather than left implicit.
September holds the autumn equinox itself, marked in the modern Pagan Wheel of the Year as Mabon and in Japan as the grave visiting weeks of Higan, alongside the fixed Christian feasts of the Nativity of Mary, the Exaltation of the Holy Cross and Michaelmas. October's religious calendar concentrates on its final day, where All Hallows' Eve, the vigil of All Saints, shares the date with the Gaelic Samhain and with Reformation Day, while Catholic devotion keeps the whole month for the rosary and the season carries most of the great Hindu autumn festivals. November opens with Western Christianity's All Saints and All Souls, answered by Mexico's Day of the Dead and Slavic Dziady, before the month closes as the year turns toward Advent.
Read together the three months trace one seasonal arc from the equinox itself through a month given over to the dead, to a close that already anticipates winter's approaching liturgical season. The dead honoring cluster running from October's end through November's opening, kept independently by Western Christian, Mexican, Gaelic and Slavic calendars, is the grouping's clearest common thread.