Bealtaine, the 1st of May, was one of the most important of the four quarterly feasts of the ancient Celts, as it marked the start of summer and the beginning of the â??light halfâ?ť of the year when the daylight grows long and all living things flourish.

Bealtaine means "fire of Bel" and is reference to the Celtic solar god, Belenos, who was venerated throughout Europe. The ancient Celtic year was thought of in two halves: gam (cold, winter) and samon (warm, summer), which also corresponded to dark and light, rest and work, female and male. Winter was associated with death, but it was also the time of rest and regeneration necessary for rebirth.

Within the major divisions of dark and light, the ancient Celtic year was divided into four seasonsâ??winter, spring, summer, and harvestâ??based on the needs of a herding and farming culture rather than the position of the sun. Each season began with a festival: Samhain (1 November), Imbolc (1 February), Beltaine (1 May), and Lughnasa (1 August).

The major feasts may originally have been movable feasts, with the exact day of celebration based on some variable in the environment. However, with the adoption of the Julian calendar and the later Gregorian calendar, the Celtic feasts were stabilized and tended to be celebrated on the Sunday closest to the quarter-day.