I'm not sure, but I don't think we need to adhere to any single, rigid style for the timeline. I think (hope?) there's wiggle-room so we can adapt it to our writing styles.

NO! You must do it my way! Kidding, of course.

All you're expected to do in this assignment is figure out when stuff happens in time, which may or may not be when it happens in the book. Sometimes we tell stories out of order deliberately through flashbacks and flash forwards. Sometimes pesky side plots make it hard to keep the timing of things straight. Could Frodo & Company have walked to Mordor in two days? Not on your life, even if there weren't hazards on the road, and it's important to know that before you launch into the writing. What were Sauron and Saruman and Galadriel and the citizens of Minas Tirith doing while they were on the road? Whatever it was, their lives need to converge with those of the protagonists at the right points in time. If Gandalf had walked in on Saruman building an orc army, I doubt Sarumun could have trapped him on the roof so easily. Gandalf might have been a little suspicious.

Cheers,
Michelle