There is no 0 AT or 0 PA, just like there is no 0 BC or 0 AD.

Ansur lived 60,000 years ago. Let us consider Ansur's death the end of humanity's journey, and let us consider Ansur's death also the final event marking the foundation of Ansus.

Let 1 AT be the year when this event happened. Let the year after that be 1 PA. AT and PA function like BC and AD, respectively.

Therefore, the year at the time of the roleplay would be approximately 60000 PA. This means that Altim died in 58063 PA, and Daen lived around 30000 PA.

[i]Edit[/i]: In the roleplay, of course, it would be customary to say "thirty thousand years after Ansur walked the Earth" or describe the date relative to previous events rather than say "30000 post Adventum."