Which two cultures are best known for its development of calendars?

Which best explains how the compass made voyages of exploration possible? How old is the roman empire? How did the European powers strengthen their economies in the 1500s and 1600s? How did things change for the Romans after Hannibal defeat? What is the origin of the name Margaret? How did enlightenment start revolutions? What day of the week was August 9 1945? Who was on the throne in the 1600's? Which event on the time line was most important for spreading the ideas of the Renaissance and Reformation? How did european settlers treat the natives of north america? What are common of silence and curtain? Who sold the slaves to the Europeans? What are the bodies of water in medieval Europe? When did roll up the rim start? What was the year 4 decades ago? Which language family is most closely related to the founding of western civilization? What was life like to women in 1600-1650's? Who went on a Crusade? What causes change in civilization? What role did the wealth of the medieval church play in european politics?