The Bhikṣuṇī Maṇimēkhalai

87 - The Historical Materials
The accepted date of the Buddha’s birth is the Nakṣatra Vaiśāka, and
the full moon day of Vaiśāka (month). The asterism referred to
therefore is Vaiśāka. This is said here in the poem to be the one
following the thirteenth, that is, the fourteenth asterism. This would
be the fourteenth only if we count it from and not from Aśvini.
The point immediately arises whether this statement has reference to
the period anterior to the days of Varāhamihira who is said to have
introduced ‘Aśvinyādi calculation’, that is, counting from Aśvini,
instead of from . Probably it was so; at the same time it is
possible to argue that this is a statement taken from current northern
tradition, and may have reference to any period since the time of the
Buddha. If the author is merely quoting a current tradition like that, it
could offer us no test of time.
The next reference is in canto XII where a prediction is made that
‘1616 years after the time the Buddha will appear.’ There are other
references besides in the body of the work to the appearance of the
Buddha. In fact, it is a stock story. Kōvalaṉ and Kaṇṇakī were to be
born when the Buddha appears on earth in northern Magadha and,
becoming his direct disciples, were to attain to nirvāṇa.
Maṇimēkhalai was also informed that she would come to the end of
her present existence in Kāñcī, and, after a number of births, she
would be born [53] a man in northern Magadha when the Buddha
should be preaching there, and, becoming his first Sāvaka (Śrāvaka)
disciple, would attain nirvāṇa. All these references are of the nature
of predictions and have reference to the coming Buddha, not to the
Buddha that had actually come and gone. These cannot be drawn into
evidence for purposes of chronology.