Luke has information suggesting that the beginning of Jesus’ story coincides with Quirinius’ census
that was carried out in Judea after Archelaus was deposed and banished: Luke 2:2f. However, this date – 6 AD – does not relate to Jesus’ birth, but to the start of his public ministry.
If we follow this interpretation, the date agrees with John’s chronology: Jesus began his public work in 6 AD at the age of 30. In this way the chronological information found in John’s and Luke’s Gospels can be harmonised.
Because if Jesus was born in 24 BC, he was 30 years old in 6 AD and about 50 years old in 27 AD (John 2:20 and 8:57).