One of the biggest questions people have in regards to the Shattering patch that took place at the end of Wrath of the Lich King is just how much time passed in game during those events. Unfortunately, there aren't any concrete answers to that question, which makes trying to muddle out time lines a little more difficult than usual. The official time line on the original World of Warcraft website was removed when the site underwent its major facelift, and a new time line was never implemented.
However, taking a look at the old time line over on Wowpedia seems to indicate that Blizzard likes patches to last approximately one year in the Warcraft time line. So classic World of Warcraft and all the events we encountered, from Molten Core to the original incarnation of Naxxramas, took place over the span of one year in the time line. The Burning Crusade and all events associated with it also took one year to complete. It stands to reason that Wrath of the Lich King would follow the same trend. But again, without concrete confirmation, we've got no way of really knowing for certain.
That said, the novel The Shattering seems to take place over the course of at least a few months or so, if not more, so there was a bit of a time jump between old-world Azeroth and the Azeroth that was implemented in patch 4.0.3a. And now, let's continue on with what went down in that novel, shall we?
Today's Know Your Lore contains pretty much every possible spoiler that exists for the novel The Shattering by Christie Golden. If you're avoiding spoilers, turn away now!