Samhain
31 October – 1 November
Samhain marked the end of the harvest and the beginning of the dark half of the year in medieval Irish reckoning. Cattle came down from summer pasture, the year's accounts were settled, and the boundary between the living and the dead was held to be at its thinnest.
Much of the modern Halloween apparatus descends from it by way of Scottish and Irish emigration: guising, turnip lanterns that became pumpkins on arrival in North America, and door-to-door rhyming for food.
The Irish literature is unusually rich here. Several of the great sagas are explicitly set at Samhain, using it as the hinge on which otherworldly events turn.