At sunset today (October 31, 2012), a significant holiday on the religious calendars of Wiccans and other Neopagans will begin. However, which particular Wiccan holiday it happens to be will vary, depending upon which particular hemisphere of the world — the northern, or the southern — you happen to reside in.

In the Northern Hemisphere, it is Samhain (pronounced “Sow-en”). In the Southern Hemisphere, it is Beltane.

(Since the season prevailing in one hemisphere is always the opposite of the season prevailing in the other hemisphere, seasonal holidays between the two hemispheres are staggered or out of sync from each other by some six months. So, by way of example, when the spring equinox occurs in the Northern Hemisphere, the autumn equinox occurs in the Southern Hemisphere — and vice versa.)

As I write, Wiccans and other Neopagans in the Northern Hemisphere are today preparing for the sundown arrival of Samhain, while their fellows in the Southern Hemisphere are simultaneously anticipating the advent of Beltane.

The natural cycle of the seasons is referred to among contemporary Pagans as “the Wheel of the Year,” and Wicca’s eight Sabbat festivals are spaced evenly around the perimeter of that wheel.

Of these eight annual Sabbats, four are classed as “lesser,” and four as “greater.” The two equinox festivals of Mabon (fall or autumnal) and Ostara (spring or vernal), together with the two solstice festivals of Yule (midwinter) and Litha (midsummer), comprise the lesser Sabbats. The Wheel of the Year is completed by the four greater Sabbat festivals of Samhain (Summer’s End), Imbolc or Candlemas (Brigid’s Day), Beltane (May Day), and Lammas or Lughnasadh (First Harvest).

As two of Wicca’s four greater Sabbats (or “fire festivals,” or four “cross quarter days”) — all four of which are distributed midway between the annual equinoxes and solstices (the four seasonal “quarter days”) on the Wiccan religious holiday calendar — Samhain and Beltane fall directly opposite each other on the Wheel of the Year. So, whenever one festival is being celebrated in one hemisphere (e.g., Samhain in the north), its polar-opposite counterpart (e.g., Beltane in the south) is being simultaneously celebrated in the other hemisphere.

Samhain, halfway between the autumnal equinox and the winter solstice (and which, in the Northern Hemisphere, begins at sunset today), is essentially a festival commemorating the conclusion of summer, the end of harvest time — and, with that, the subsequent increasing dimming of the sun. As such, Samhain is a festival of approaching darkness, of deepening and lengthening shadows; it is traditionally a time for reflection, and for paying respects to the spirits of one’s ancestors.

It is said that the veil between the worlds of the living and the dead grows thin at this time of year (as it also does at Beltane), and the dead may even be invited to join in the Samhain festivities. In northern latitudes, Samhain is closely associated with Halloween; the Samhain festival is, in fact, the actual source of the ancient pagan roots of our own modern, spooky, costume-wearing, candy-gathering “Trick or Treat” festivities.

Beltane, halfway between the vernal or spring equinox and the summer solstice (and which, in the Southern Hemisphere, begins at sunset today), is Samhain’s polar opposite, marking the return of summer. In northern latitudes, Beltane is historically a “first day of May” festival, and is essentially an optimistic celebration of light and fertility, traditionally observed with bonfires and maypole dancing.

So, to my Wiccan friends and readers in the Northern Hemisphere: “Blessed Samhain!”

And to my Wiccan friends and readers in the Southern Hemisphere: “Blessed Beltane!”