The date of the Buddha's birth is calculated differently across different Buddhist traditions and by modern historians. A long chronology, widely used within Theravada Buddhism and tied to the traditional 544 or 543 BCE date given for his death, or parinirvana, places his birth around 623 BCE, assuming an eighty year lifespan the tradition consistently attributes to him. Modern historical scholarship has increasingly favored a revised, shorter chronology, developed through more critical comparison of Buddhist, Jain and other regional chronological traditions, and formalized at a 1988 academic symposium in Gottingen, which places his death closer to 400 BCE and his birth correspondingly around a century later than the traditional long chronology suggests.
Neither chronology rests on independent, externally dated evidence in the way later, better documented periods of South Asian history do, and the disagreement reflects the same broader difficulty scholars face across early Indian religious history: traditional chronologies preserved within a religious community often diverge significantly from chronologies reconstructed through comparative and archaeological methods, without either approach being able to produce fully conclusive independent confirmation.
The Buddha's existence as a historical individual is not seriously questioned by scholars, distinguishing this uncertainty from more fundamental historicity debates that apply to some other ancient religious founding figures; what remains genuinely unsettled is the precise dating of his life relative to the modern calendar.