Re the Boston changeover, I wondered about that as well as I did see archibaum's post saying mid December-January but late November seat maps are showing 340-600's.
Here's the full winter schedule for VS11/12: 31/10/04-15/12/04 343 days 1/2/3/4, 346 days 5/6/7 16/12/04-15/01/05 343 days 1-7 16/01/05-06/03/05 343 days 1/2/3/4, 346 days 5/6/7
VS11 dep time changes from 1500 to 1430 for the winter.
So the changeover is actually 31Oct...my post referred to by mcuth was just relating to the Xmas period.