The US National Counterterrorism Center is pleased to present the 2015 edition of the Counterterrorism (CT) Calendar. This edition, like others since the Calendar was first published in daily planner format in 2003, contains many features across the full range of issues pertaining to international terrorism: terrorist groups, wanted terrorists, and technical pages on various threat-related topics. The Calendar also marks dates that terrorists may believe are important if planning attacks to commemorate particular events. Under US law, NCTC focuses exclusively on international terrorism. There are other organized groups that engage in violent acts-some are criminal organizations with no political or social agenda, and some are domestic terrorist groups; however, this calendar reflects NCTC's international focus. Senior Intelligence Community officials assess the greatest international terrorist threats currently facing the United States come from violent extremists inspired by al-Qa'ida, including its allies and affiliates, who are committed to conducting attacks inside the United States and abroad. These groups promote an ideology that presents a radical vision of Islam that is not followed or endorsed by the vast majority of Muslims. Individuals portrayed in this calendar are all listed on the US Government's Rewards for Justice site or on FBI sites devoted to terrorism. These individuals have been either indicted or are being sought for their involvement in international terrorism.