The magical world and Iris Academy in particular celebrate many holidays, some of which are like normal ones and some aren't.
Halloween - There are no costumes, candy, or trick-or-treating, but Halloween is the night of the Dark Dance, a celebration that is held in the dark so that spirits can visit without being seen. The next day is a hoilday from class.
Apple Day - this is a local custom but not magical
Canadian Thanksgiving - Is mentioned but not celebrated.
Thanksgiving - There are a few days of no classes so that students can go home for Thanksgiving break. Before the break the school holds fundraisers to gather money from nonmagical people as part of a tribute the school pays to the local tribal councils. There is also a Thanksgiving blessing before break.
Christmas - Appears to be celebrated. The students go home for Christmas break and the freshmen make cards for each other as part of a Secret Santa exchange.
Martin Luther King Jr. Day - Is a class holiday but doesn't have any other celebration.
Valentine's Day - Appears to be celebrated normally.
New Years - takes place in February, not December/January, and involves a bonfire.
Maple Ceremony - a pancake supper that is part of an old romantic custom. only unmarried people can take part.
May Day - the final ball