Dale Reckoning (DR)
There presently exist at least a dozen different calendrical systems in use on Abeir-Toril. Dale Reckoning (DR) is the closest such system to a worldwide standard.
The system begins counting years at 1 DR. The event selected for this date is when the Standing Stone was raised by the elves of Cormanthyr and the human Dalesfolk.
Narrative
The first campaign begins on 1355 DR.