The Maya civilization was located in Mexico, Guatemala, and northern El Salvador. They had complex social, political, and economic systems between 2000 BC and 900 AD, with trade, cultivation, and a hierarchical society. Their religion included ceremonies, dances, songs, fasting and human sacrifice. They developed hieroglyphic writing, mathematics, astronomy, and a precise calendar. While the classical Maya civilization ended, the modern Maya people still live in the region and speak Mayan languages. There was speculation that the world would end according to the long-count Maya calendar on December 21, 2012, but this did not occur.