A few thoughts on time keeping, history and calendars:

In the past, elves have ruled of Kaledan, but as climate changed for the wotse, their kingdoms waned in power and as humans came to the scene, they where pushed back little by little. These conflicts have caused friction between the modern humans and elves.

What if elves used lunar calendars and Azter-like calendar, using, for example, a century-long (or other similar period) as a basic unit of a cycle and naming it after a major historical event. As they live longer than your avarage human, they have a better perspective on history, and would refer different times as Ages.

Humans have used solar calendar for centuries, similar to the Gregorian calendar, but of course, with a different name.

Edit: we also need some kind of timeline. It can be rough, but I'd like to include such factors like immigration waves, formation of kingdoms, wars, importan individuals, founding of towns/cities/castles, royal houses and such.