The magic bands should ship a day or two after the customization period ends but being so close you might not be able to customize them. They'll ship from some place in the midwest (Tennessee or Kentucky, it think?), not from Florida which was what I was expecting.
If you are a compulsive package tracker like me, the shipping will infuriate you, it'll stay in places for 2-4 days and then finally move but we've never had an issue where they haven't made it on time, even with "shipping exceptions" due to weather while in transit.