Do new iphones sell out in stores on release date?

I really want the new iphone 5s on the release date, and I'm prepared to wag school for it, but is it worth it?
Typically, do new iphones sell out on release date? If i got to the store at about 4.30pm, would all the phones be sold out by then? Or should i go early at 9am to be safe?

Do any of you know if iphones typically sell out on release days, specifically in Australia?

Added (1). I know its released on sep 20, but i want to know if it will all sell out by 4pm or not. 16gb gold to be specific

On setp 20

Go to an apple store if you can as they always have more supply.

Yes they do sell out on launch day usually. At about 4:30 it would likely be sold out or a long enough line that getting it would be a long wait.