Monday 17 Jan Martin Luther King, Jr.Day
Monday 21 Feb Washington"s Birthday/Presidents' Day
Friday 22 Apr Good Friday
Monday 30 May Memorial Day
Monday 4 July Independence Day
Monday 5 Sep Labor Day
Thursday 24 Nov Thanksgiving Day
Monday 26 Dec Christmas Day (observed)
Note: * New Years' Day (January 1) in 2011 falls on a Saturday. The rules of the applicable exchanges state that when a holiday falls on a Saturday, we observe the preceding Friday unless the Friday is the end of a monthly or yearly accounting period. In this case, Friday, December 31, 2010 is the end of both a monthly and yearly accounting period; therefore the exchanges will be open that day and the following Monday.
** Each market will close early at 1:00 p.m. on Friday, November 25, 2011 (the day after Thanksgiving). Crossing Session orders will be accepted beginning at 1:00 p.m. for continuous executions until 1:30 p.m. on this date.
Source: http://www.nyse.com/Frameset.html?displayPage=/about/1022963613686.html