Below is the timeline of events that have happened in Hyrule's past. You will see years with both "B.G." and "A.G." after them. These refer to "before Ganon" and "after Ganon" respectively. When Ganon invaded Southern Hyrule, the system that the Hylians used to keep track of years was discarded and replaced with this one. Ganon invaded in 1 A.G, and anything before that event or after that event is refered to accordingly.