School holiday or winter break is a period when educational institutions are closed for a period in late December into early January.
During this time frame high school, junior, collegiate, and university hockey traditionally hold tournaments with 4 to 6 teams playing at a single site over the course of 2 to 4 days with a single team winning the tournament.
The IIHF World U20 Championship or World Junior Hockey Championship is held in this time frame with games usually starting on December 26th (Boxing Day in the British Commonwealth) when only one arena is available it usually starts on December 25th (Christmas Day). The Canadian and American teams traditionally play their round robin game on December 31st (New Year's Eve).