The four solar festivals – the Winter Solstice, Spring Equinox, Summer Solstice, and Autumn Equinox – divide the year into quarters. Known as the Quarter Days or Lesser Sabbats, they fall at the height of each season in the old reckoning, and their dates shift a little each year with the Sun’s passage.

Between them fall the four fire festivals of Gaelic tradition: Samhain, Imbolc, Beltane, and Lughnasadh, known in England as Lammas. These are the Cross-Quarter Days, or Greater Sabbats. They keep fixed dates, an anchor in the ebb and flow of nature, and mark the year’s greatest seasonal shifts.