After the just mentioned account of Buddha in the text, the commentator says, ‘He became visible, the-thousand-and-second-year-of-the-Cali-age being past; his body of-a-colour-between-white and-ruddy, with two-arms, without-hair on his head.’ ” There is a calculation mistake in the date though, as 1002 years from the beginning of Kali age would be 2100 BCE and not 2009 BCE as quoted by Sir William Jones.
On the other hand, Pandit Kota Venkatachelam calculated the year of birth to be 1887 BCE .
Both of these works are based on the assumption that Kaliyuga started in 3102 BCE, though their interpretations of Paurāṇic chronology are different.
The currently accepted year of birth of Buddha was calculated based on the identification of the Indian king Sandrokottos from Greek accounts with Chandragupta Maurya by Sir William Jones in 1793 CE .
In 1788 Sir William Jones weighed the various sources and accepted 1027 BCE as the date of the Buddha’s birth. Harrington considered the Singhalese date to be credible as the Singhalese sacred era was reckoned from it and the date matched Siamese era very well.
As quoted above, one work Bhāgavatāmṛita gave 2009 BCE as the year of birth of Buddha.
This was the work that was quoted by Pandit Rādhākānta to Sir William Jones in eighteenth century : “These ten Avataras are by some arranged according to the thousands of divine years in each of the four ages, or in an arithmetical proportion from four to one; and, if such an arrangement were universally received, we should be able to ascertain a very material point in the Hindu chronology; I mean the birth of Buddha, concerning which the different Pandits, whom I have consulted, and the same Pandits at different times have expressed a strange diversity of opinion. Kalki) is yet to come, and that Buddha was the last considerable incarnation of the Deity; but the astronomers at Varanes place him in the third age, and Radhacant insists that he appeared after the thousandth year of the fourth.
However, the same Singhalese texts that mention 218 years between the Nirvāṇa of Buddha and coronation of Piyadassi are also emphatic that Nirvāṇa of Buddha took place in 543 BCE.
Counting from this date the coronation of Aśoka Maurya took place 218 years later in 325 BCE, which is around the time of the invasion of India by Alexander.
Modern historians are telling us that the place farthest from the birthplace of Buddha has preserved the most authentic date of his birth.