Stock markets around the world open and close at different times, according to WiseStockBuyer.com. Normal hours for the New York Stock Exchange and NASDAQ, the two major stock markets in the United States, are from 9:30 a.m. to 4 p.m. Eastern Time.
The first stock exchanges to open are the Tokyo Stock Exchange and the Korea Stock Exchange, notes Wikipedia. Both open at 9 a.m. local time or 0:00 Coordinated Universal Time. The last four to open and close are in North America: the NYSE, NASDAQ, Toronto Stock Exchange and Mexican Stock Exchange. All four open at 14:30 and close at 21:00 Coordinated Universal Time.