Calan Mai
Calan Mai ([ˈkalan ˈmai̯] 'first day of May') or Calan Haf ([ˈkalan ˈhaːv] 'first day of Summer'), also historically called Cyntefin, 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.