According to currency trading fo dummies-;
Around the World in a Trading Day
The forex market is open and active 24 hours a day, from the start of business hours on Monday morning in the AsiaPacific time zone straight through to the Friday close of business hours in New York. At any given moment, dependingon the time zone, dozens of global financial centers — such as Sydney, Tokyo, or London — are open, and currency trading desks in those financial centers are active in the market. In addition to the major global financial centers, many financial institutions operate 24-hour-a-day currency trading desks, providing an ever-present source of market interest. It may be a U.S. hedge fund in Boston that needs to monitor currencies around the clock, or it may be a major international bank with a concentrated global trading operation in Singapore.
The opening of the trading week There is no officially designated starting time to the trading day or week, but for all intents the market action kicks off when Wellington, New Zealand, the first financial center west of the international dateline, opens on Monday morning local time. Depending on where you live, it roughly corresponds to early Sunday afternoon in North America, Sunday evening in Europe, and very early Monday morning in Asia. The Sunday open represents the starting point where currency markets resume trading after the Friday close of trading in North America (5 p.m. eastern time [ET]). This is the first chance for the forex market to react to news and events that may have happened over the weekend. Prices may have closed New York trading at one level, but depending on the circumstances, they may start trading at different levels at the Sunday open.