thumb|A maypole at [[Llanfyllin, Montgomeryshire (now Powys) on 1 May 1941]]
( 'first day of May') or ( 'first day of Summer'), also historically called , is the Welsh celebration of May Day (1 May). It marks the beginning of summer and traditionally it involved festivities around bonfires, maypoles, and carol singing. Some of its traditions parallel the Gaelic May Day festival Beltane, and other May Day and Walpurgis Night traditions in Europe.
Customs
Traditionally, bonfires () were lit at in parts of Wales. They were lit in Glamorgan until the 1830s. Nine men would gather branches of nine different trees, remove all metal, then light the fire by friction between wood. A fire kindled in such a way is known as a need-fire. Sometimes two fires were built side-by-side. Round cakes of oatmeal and brown-meal were sliced and placed in a bag, and participants each chose one; those who chose a brown-meal slice had to leap three times over flames, or run thrice between the bonfires. This was believed to ensure a good harvest. bonfires were also recorded in Montgomeryshire.
Small groups of young men went about singing May carols () or summer carols () at , and were rewarded with food and drink.
- In Anglesey and Caernarfonshire it would be common on May Eve to have 'playing straw man' or 'hanging a straw man'. A man who had lost his sweetheart to another man would make a man out of straw and put it somewhere in the vicinity of where the girl lived. The straw man represented her new sweetheart and had a note pinned to it. Often the situation led to a fight between the two men at the May Fair.
- May Day was the time that the or 'tump for playing' (a kind of village green) was officially opened. Through the summer months in some villages the people would gather on the in the evenings to dance and play various sports. The green was usually situated on the top of a hill and a mound was made where the fiddler or harpist sat. Sometimes branches of oak decorated the mound and the people would dance in a circle around it.
- Common drinks during Calan Mai festivities fermented honey (mead) sometimes flavoured with herbs or spices (). Sometimes it was made of herbs, including woodruff, a sweet-smelling herb which was often put in wine in times past to make a man merry and act as a tonic for the heart and liver. Elderberry and rhubarb wines were popular as well as various beers.