- last post: 01.01.0001 12:00 AM PDT
I think it really depends on how much they are going into the Battle of Reach with this game. The battle lasted from August 30, 2552 with the Fermion detecting the Covenant fleet and it ended on September 23, 2552 with the Covenant glassing Reach and the Pillar of Autumn making a Slipspace jump to Installation 04 which is where Combat Evolved began.
I'm not sure how much time was spent on the first Halo ring, but this battle lasted nearly a month so it's hard to tell.