[sourcery]

In the year 2489 after the creation of the Universe, 40 years after the exodus of the Children of Israel from Egypt, and after they had crossed the Jordan River in a miraculous way, on the 14th Nissan they made the Pesach Sacrifice and celebrated Pesach and ate matzah as G-d had commanded them as a memorial of the exodus.

Nisan 14, 2489 AH => April 8, 1271 BC [Proleptic Gregorian]

[sourcery]

"Nisan 14, 2489 AH"

Oops. Change "AH" to "AM" (Anno Mundi, 'year of the world')