Father Erlenbush at New Theological Movement has a great post on Saint Gabriel and Daniel's seventy weeks. Please check it out. Father explains how Catholic tradition identifies these "70 weeks" as the 490 years from "the going forth of the word" of King Artaxerxes to rebuild the Temple in Jerusalem until the ministry of Christ our Lord.
By the way, the medieval Rabbis forbade Jews to calculate the years of Daniel? Why? The answer is obvious - by calculating the dates of Daniel, Jews would discover that Daniel's Son of Man would have begun his ministry in the first half of the first century...that is, they would discover that Jesus is the Messiah.
There is another mystical reading to the seventy weeks of Daniel. There are approximately seventy weeks (490 days) from the prophecy of Saint Gabriel in the Temple to St Zacharias, the father of John the Baptist, until the presentation of Christ in the Temple.
Here's the math in case you're skeptical:
Elizabeth was 6 months pregnant when Mary conceived (24 weeks)
Mary was pregnant 9 months (40 weeks)
Christ presented at Temple 40 days after birth (6 weeks)
24 + 40 + 6 = 70 weeks
I'm not at all claiming that the traditional reading of the "490 years" is incorrect. No, in fact, this is the authoritative reading. But there is something interesting going in Luke's Gospel since both Daniel and Luke record the ministry of Saint Gabriel, and Saint Luke records a nativity-temple-chronology that comes to about "seventy weeks."
St Gabriel, pray for us.
Daniel the Prophet, pray for us.
St Zacharias, pray for us.
PS: In the next few days I'll be writing a post to show how Saint Luke's chronology means that Christ HAD TO BE BORN IN LATE DECEMBER! Stay tuned. Please subscribe for free via reader or by email.