The IIHF World U20 Championship, commonly known as the IIHF World Junior Hockey Championship (WJC), or simply the "World Juniors" in ice hockey circles, are an annual event organized by the International Ice Hockey Federation (IIHF) for national under-20 ice hockey teams from around the world. They are traditionally held in late December, ending in early January. The tournament usually attracts top hockey players in this age category. However, some NHL teams do not release their top players as the tournament overlaps with the NHL season.