What it is
New Year's Day marks the first day of the calendar year. For most Americans it is the quietest holiday of the year: offices, banks, schools and the stock market close, and the day is spent recovering from New Year's Eve, watching college football bowl games or starting resolutions.
Is it a day off?
Federal employees get the day off. When January 1 is a Saturday, the federal day off is the Friday before, which means it lands on December 31 of the previous year. That happens in 2028, 2033 and 2039. When January 1 is a Sunday, the day off moves to Monday, January 2.
Nearly every private employer that offers paid holidays includes New Year's Day. The New York Stock Exchange closes on January 1, but it does not close on the Friday before when the holiday is a Saturday, so December 31 is a normal trading day in those years.
History
Congress made New Year's Day a holiday for federal workers in the District of Columbia in 1870, together with Independence Day, Thanksgiving and Christmas. Those four were the country's first federal holidays.