Samhain step from guising to playing pranks". Playing pranks at Samhain is recorded in the Scottish Highlands as far back as 1736 and was also common in Ireland, which led to Samhain being nicknamed "Mischief Night" in some parts. Wearing costumes at Halloween spread to England in the 20th century, as did the custom of playing pranks, though there had been mumming at other festivals. At the time of mass transatlantic Irish and Scottish immigration, which popularised Halloween in North America, Halloween in Ireland and Scotland had a strong tradition of guising and pranks. Trick-or-treating may have come from the custom
Samhain Stokes suggested an etymology from Proto-Celtic "*samani" ("assembly"), and Joseph Vendryes suggested that it is unrelated to "*semo-" ("summer"), because the Celtic summer ended in August. The Gaulish month name "(pertaining to) Summer" on the Coligny calendar is likely related to the word "Samhain". A festival of some kind may have been held during the 'three nights of "Samonios"' (Gaulish "trinux[tion] samo[nii]"). The Gaulish calendar seems to have split the year into two-halves: the first beginning with the month and the second beginning with the month , which is related to the word for winter, PIE "*g'hei-men-" (Latin "hiems", Latvian