The Day after Thanksgiving is not an official holiday; however, the market has a tradition of closing at 1:00 p.m. on this day.
When any holiday that is observed by the stock market or stock exchange falls on a Saturday, then the market will not be open for business on the proceeding Friday.
When any holiday that is observed by the stock market or stock exchange falls on a Sunday, then the market will not be open for business on the following Monday.
New Year's Day (January 1)
Good Friday (the Friday before Easter Sunday, which moves around depending on the lunar calendar)
Independence Day (July 4 or there abouts)
Labor Day (September 1?)
Thanksgiving (November 27)
Christmas Day (December 25)
Martin Luther King, Jr. Day is celebrated on the third Monday in January
President's Day is celebrated on the third Monday in February
Memorial Day is celebrated on the last Monday in May