Universal Timeline

I have three timelines

A mythic timeline based on the arrival of the Ark. Spans approximately 3500-5500 years... not much in the way of disrete events. Lots of proximal eras or ages.

Year of the Goddess is based on the foundation of the Theocracy of Quzonia and the begginings of widespread Goddess worsahip. Canon current to 802 YG.

Wejiran Reckoning is based on the formation of the empire from the Seven Cities. They do not believe in the Twinned Goddess, so they do not follow that timeline. Cannon current to 1257 WR.

Local custom is to account for the year by reign of monarch and dynasty as appropriate within each nation.

As the omniscient narrator for the world I tend to use BG/YG for most events. Although a CE format might be better for consistent timelines and local accounting within the actual world narrative. -- In my meta/canon I use the arrival date of humanity (or rather the second arrival of humans aboard The Ark. Year of the Ark, YofA, YA. Individual cultures date the current year off the dynastic monarch model, until the mythic revelation of the Goddess. In those Gooddess worshipping cultures a Before Goddess/Year of Goddess convention is used. The Ark event is buried in the mists of time, predating the mythic God Wars. Only oral records exist as ancient stories and myth. So no one counts from that. --