The timers won't match up because this is an event that didn't autostart for every player at the same time. There are nine days left in total for the event but that's only true for players who waited until the goal force started (which was days after the event launched).
Each player's specific timer is started from the moment they clicked "Begin" and started the first chapter. From there, the ten day counter started ticking down. Your exact time left should be the one at the top of the chapter book icon on the right hand side of the screen (the little red curtained stage with the reindeer) or if you open the chapter book, it will appear at the top left above the reindeer's head under the title "Event Expires In:"