The global currency markets are affected by global news, events and financial announcments. That´s why it´s so interesting to trade forex: knowledge is power. Many people use the calendar to close out their positions before big announcements like the US NFP (Non-Farm Payroll, employment numbers) to avoid the volatility that can sometimes occur during these events. Another strategy is the News Fade, where you enter the market 15 minutes or so following a news announcement spike, or trough, in the hope that it fades away.
Here is a calendar of all the up and coming announcements that may help your trading.