I probably hung it for an hour. I ended up rushing it, as I meant to cook it when I got home, but soon realized I was going to have to mow the yard first. When I finished mowing, a storm was setting in, which caused me to rush things. I was also a little short on the charcoal, as I usually fill the basket, even when doing a smaller cook like this.
As always, the coals were perfect for cooking after I was already done. :-)
My guess is that if the coals had been farther along when I started, it would have taken 30-40 minutes.