May Eve, the eve of the first day of summer in the Northern hemisphere (see May 1): Beltane begins at sunset in the Northern hemisphere, Samhain begins at sunset in the Southern hemisphere. (Neo-Druidic Wheel of the Year)
Beltane
Beltane or Bealtaine is the Gaelic May Day festival, marking the beginning of summer. It is traditionally held on 1 May, or about midway between the spring equinox and summer solstice. Historically, it was widely observed in Ireland, Scotland, and the Isle of Man. In Ireland, the name for the festival in both Irish and English is Lá Bealtaine. In Scottish Gaelic it is called Là Bealltainn, and in Manx Gaelic Boaltinn or Boaldyn. It is one of the four main Gaelic seasonal festivals—along with Samhain, Imbolc, and Lughnasadh—and is similar to the Welsh Calan Mai.
Samhain
Samhain or Sauin is a Gaelic festival on 1 November marking the end of the harvest season and beginning of winter or the "darker half" of the year. It is also the Irish and Scottish Gaelic name for November. Celebrations begin on the evening of 31 October, since the Celtic day began and ended at sunset. This is about halfway between the autumnal equinox and winter solstice. It is one of the four Gaelic seasonal festivals along with Imbolc, Bealtaine, and Lughnasa. Historically it was widely observed throughout Ireland, Scotland, and the Isle of Man. Its Brittonic Celtic equivalent is called Calan Gaeaf in Wales.
Druidry (modern)
Druidry, sometimes termed Druidism, is a modern spiritual or religious movement that promotes the cultivation of honorable relationships with the physical landscapes, flora, fauna, and diverse peoples of the world, as well as with nature deities, and spirits of nature and place. Theological beliefs among modern Druids are diverse; however, all modern Druids venerate the divine essence of nature. While there are significant variations in the expression and practice of modern Druidry, a core set of spiritual and devotional practices may be observed, including: meditation; prayer/conversation with deities and spirits; the use of extra-sensory methods of seeking wisdom and guidance; the use of nature-based spiritual frameworks to structure devotional practices and rituals; and a regular practice of nature connection and environmental stewardship work.