Here's a link to the official U.S. Federal government list:
U.S. Federal Holidays 2010 For Federal government purposes, Christmas Day is a holiday (observed on Friday this year because it falls on Saturday), but Christmas Eve is not. Boxing Day is not recognized in the U.S.
The complication is that individual states have their own holiday schedules, so you could make New Troy have any schedule that works for your story. Private businesses also are free to set their own schedules. For example, my husband works for a private Catholic university, so, although not a federal holiday, they always have Good Friday off. And, because our area is highly Catholic, the public schools also take Good Friday off, even though it's not a federal holiday. In areas with large Jewish populations, the public schools will often take off for the major Jewish holidays, etc.
HTH,
Happy
