"The US National Counterterrorism Center is pleased to present an interactive version of the 2008 Counterterrorism Calendar. This version of the Calendar contains many features across the full range of terrorism-related issues: terrorist groups, wanted terrorists, and technical pages on various threat-related issues. The Calendar timeline marks dates according to the Gregorian and Islamic calendars, and contains significant dates in terrorism history as well as dates that terrorists may believe are important when planning 'commemoration-style' attacks. The CT Calendar is designed for anyone concerned with counterterrorism or terrorist threats; law-enforcement, intelligence, military and security personnel, contingency planners, or simply citizens concerned by terrorist threats. The Calendar is oriented primarily to readers in the United States, but we hope that we have also made it useful for citizens of other countries." The print version of the calendar is also available from the link.
U.S. National Counterterrorism Center: http://www.nctc.gov/