The only reason you would want to trade certain times of the day is if you are a scalper looking for short term trades either at market opens or during significant news events.
Worldwide Forex Markets Hours
The forex is fully electronic and open somewhere in the world between 5 p.m. Sunday and 5 p.m. Friday Eastern Standard Time (EST). Each exchange has unique trading hours from Monday through Friday. From the average trader’s perspective, the four most important time windows (all EST) are as follows:
London: 3 a.m. to 12 p.m. (noon)
New York: 8 a.m. to 5 p.m.
Sydney: 5 p.m. to 12 a.m. (midnight)
Tokyo: 7 p.m. to 4 a.m.3
While each exchange functions independently, they all trade the same currencies.5 So, when two exchanges are open, the number of traders actively buying and selling a given currency greatly increases. The bids and asks in one forex market exchange immediately impact bids and asks on all other open exchanges. That reduces market spreads and increases volatility, including in the following windows:
8 a.m. to noon, with both the New York and London exchanges open
7 p.m. to 2 a.m., with both the Tokyo and Sydney exchanges open
3 a.m. to 4 a.m., with both the Tokyo and London exchanges open
The New York exchange is especially important for foreign investors. Its trades involve the U.S. dollar, which is involved in 90% of all currency trades. Movements of the dollar can have a strong ripple effect around the world
Either way, keep a list of major news events in your calendar and stay aware of when the market opens and plan your trading session around each of these events.