Originally Posted by 2StgTurbine

They are very flexible in working around your schedule. The earliest they can get you in is typically 3-5 weeks. I know one person had to call them back to delay their interview by another month and they were fine with that.

And as far as getting "ready." You should not be waiting until they call, you should start preparing now. This is not something your cram for. You want the days or weeks leading up to the interview to be stress free.