Q. Why does Judaism call the new year 5769, not 2008?
A. 2008 is a Christian date supposedly deriving from the birth of Jesus, though he was actually born in 3 or 4 BCE.
5769 is the number of years since Creation, when understood in a spiritual sense as the date when man and civilisation began. Rabbi Yose ben Chalafta (2nd century CE) explained this in his Seder Olam Rabba, a classical Jewish chronological work.
5769 (tav-shin-samech-tet) is the initials of t’hi sh’nat s’gulah tovah, “May it be a year of great influence”.