How long does it take for an iphone 4 to update to iOS 6.0.1?

I started the update at around 12:30 pm, and its already 6 pm! Its already been 6 hours! All its been doing is popping up the apple logo (the one thar pops up when you turn your iphone back on after its been off) for lets say 10 seconds, then it goes back to plain back, then back to the apple logo, & it keeps going back & forth & i'm getting impatient.

About 15 minutes to download the IPSW file and 10 minutes to install it. It would be faster on a newer device like iPhone 5 or 4S.