Under normal circumstances, the New York Stock Exchange (NYSE) schedule is from Monday through Friday 9:30 a.m. to 4:00 p.m. ET. NYSE Arca is also open from 4:00 a.m. to 9:30 a.m. ET and 4:00 p.m. to 8:00 p.m.
Most U.S. stock exchanges follow the NYSE holiday calendar in regard to days when the market is closed or observing abbreviated hours. The NYSE and its affiliated exchanges (NYSE MKT, NYSE Amex Options, NYSE Arca, NYSE Arca Options and NYSE Bonds) close for official U.S. holidays.
Although NYSE Arca follows the same holiday calendar as the NYSE, on days when the NYSE closes early, NYSE Arca hours may vary due to its extended trading day.
In addition to the days noted on the New York Stock Exchange holiday calendar, the markets sometimes also close for special occasions or emergencies.