Time, a measurable part of the universe's structure in which events occur in sequence, was regulated by Galactic Standard Calendar (which was based around the Galactic standard second) in most places within the galaxy. The invention of hyperdrive allowed spacers to bypass the laws of time and keep time dilation from happening during interstellar travel. There were a number of individuals in the history of the galaxy who actually managed to time travel in ways which defied the standard sequence. Time was ordered around the legendary conflict known as the Battle of Yavin.