For me, the current co.uk estimate is 6th - 9th. But bear in mind that (in my experience), amazon shipping dates are always a bit conservative - usually they say 2-3 days for shipping, but good postal service can easily cut 1 - 2 days.
But I dunno jack about the reliability of the US postal system, my experiences are based on the UK and German postal service - where you usually pop in a letter before 5pm and get it to the recipient one day later. Plus 1-2 days if cross-border (i.e. UK <-> Germany).
But if the local US post is as good as the post here, you have good chances to get it on Saturday (7th) or Monday (9th).
Cheers, LT