what worldfamous festival, with its roots in ireland, marks the end of the harvest season and the onset of winter, aligning with the ancient celtic celebration of samhain?

The world-famous festival that marks the end of the harvest season and the onset of winter, aligning with the ancient Celtic celebration of Samhain, is Halloween. Halloween is recognized on the 1st of November in the Northern Hemisphere, with its celebrations beginning on the 31st of October. The festival of Samhain marked the end of the Celtic year and the beginning of the new one, and as such can be seen as the equivalent of New Years Eve. The Celts believed that night preceded day, and so the festivities took place on the Eve of Samhain.