OOC: As you may have noticed, the roleplay world uses a system of years Before Common Era (BCE) and Common Era (CE). This corresponds to the BC and AD system used in real life. Year 0 BCE/CE would be the turning point between the two eras, so you might be asking yourself, what caused Year 0? Why did the roleplay world's historians decide that a particular year was the turning point in global history?
IC: Year 0 was an incredibly tumultuous year. A plague known only as the Great Plague ravaged all the continents, from Terra to the East, killing millions indiscriminately. The Kaltach, once a prosperous empire on the Eastern Continent, were forced onto the Island of Kaltach, which would become the new centre of Kaltach civilization.
The plague was not the worst thing about Year 0. An enormous earthquake separated modern-day Jazado from modern-day Cenaesia, creating the channel we know and love today. Volcanoes erupted, and islands were sunk while others were formed. Floods and locusts destroyed crops, causing massive famines around the globe. As soon as the flood-waters were cleared away, a drought began. It is estimated that around 65% of the world's population perished in the Great Catastrophe, as Year 0 is often called. The Edofasians believe that the Armageddon was caused by man going to war against the gods, and that the disasters were the vengeance of the divine. Other cultures offer different explanations, but above all, Year 0 was a truly disastrous and unique year.
It is thus the reason why it is the turning point separating the ancient world from the modern world, and the ancient era from the modern era.
OOC: Remember to write your years as "BCE" and "CE" accordingly! Since Jesus never existed in this timeline, Year 0 and the Common Era system is the best approximation we can give. You are more than welcome to share tales of your own nation's beliefs and explanations on Year 0 in the Worldbuilding forum.