Thanks Everyone - incredibly helpful information; and especially to goadra who emailed me the following timeline (goadra, if I may credit you with the following link you provided and partial text of your email):
This topic has a timeline for the film. (This timeline is not perfect--it attempts to merge the film, the story and the screenplay.)
http://bettermost.net/forum/index.php?topic=3822.0It pains me, as it must all of us, in trying to put a chronology to the story - the tragic irony of Ennis initiating the November meeting via the postcard without knowledge of Jack's death. It's hard for me to grasp the emotional impact of this.