Trading sessions:

NYSE: The New York stock exchange is the biggest stock exchange in the world in almost every possible way. It has nearly 2000 listings, its market cap is over $16 trillion and it will soon celebrate its 200th year in existence. Market leaders are traded here and the NYSE often sets the tone for the financial world.
Trading Hours: Monday-Friday 9:30am-4pm (local time)
1:30pm-8pm (GMT)

London Stock Exchange: Over 200 years old, the London stock exchange is quite possibly the oldest of all major stock exchanges; it lists nearly 3,000 companies and has trading volume that reaches $2 trillion. Its traditions and varied listings give it great credit as a trend setter and it is often considered the bridge market between east and west.
Trading Hours: Monday-Friday 08:00am-4:30pm (local time)
07:00am-3:30pm (GMT)

Tokyo Stock Exchange: The premier market in all of Asia, the Tokyo stock exchange lists primarily assets from that region of the world. With some companies holding dual listings in other major markets, with Asia’s development within the last half century, its place as an economic leader is becoming clearer with each passing day. The exchange lists over 2000 companies and handles over $4 trillion in trades annually.
Trading hours: Monday-Friday 09:00am-3:00pm (lunch from 11:30am-12:30pm) (local time)
00:00am-6am (lunch hour is 2:30am-3:30am) (GMT)