Are the estimated shipping date range always accurate?

I ordered a gold IPhone 6, 16 GB on Saturday, October 1st. It is now October 11th and the att wireless order status website still says it is "preparing to ship". My shipping dates are 11-11-14 through 11-20-14. MY question is are these shipping dates always accurate? Will my phone be here by the 20th?

No… That is why it is call ESTIMATED