Simplify the following text for a Grade 11 native English-speaking person.
Original: The estimated year of Good Friday is AD 33 , by two different groups , and originally as AD 34 by Isaac Newton via the differences between the Biblical and Julian calendars and the crescent of the moon .
Simplified: The estimated year of Good Friday is AD 33 , by two different groups , and at first as AD 34 by Isaac Newton by the differences between the Biblical and Julian calendars .