Halo 4 Time Line

Well the time line we have to deal with starts March 3 2553, ends with the noble six tribute on July 7 2589. This gives the rest of the halo series a timeline of 36 years 4 months 4 days. What could happen inbetween that time and the awakening of John 117 in the Halo 4 Trailer? Please discuss.

So ok I notice the date July 7 2589 is not listed on the Halo time lime. Here is proof http://i163.photobucket.com/albums/t285/CaNiBaLElite/H4C/H4C5.jpg and believe this date needs to be added as Cortana’s Tribute speech for Noble Six 7/7/2589. Does anyone else agree?