So the calendar will go to the printer on Monday morning (I have to finish the back cover today, and they're closed tomorrow through Sunday), it should take 2 days to get the proof, and if there are no problems, 5 days to print and 2 to ship from the printer to Ookoodook. Hence, the 11th. (That last step is also prone to delays, by the way; freight shipping seems to be a very sketchy industry in that way.) I also have the option of paying for a rush delivery, if need be, though that will be very pricey and I'll probably only do that if sales spike way above what I'm expecting and Ookoodook needs extra time to pack boxes.
So, the 11th is the projected date, and the 13th is probably the because-something-always-goes-wrong date. Either way, US customers should have their calendar in time for the holidays.