The turnaround time on permission requests depends upon (among other factors) the copyright status of the request (public domain versus third-party content) and the response time of the copyright holder.
That said, the library needs at least a 3-business-day turnaround on requests that do not require written permission. If written permission is required, this turnaround can extend to 10 days or more.
The librarian will wait 3 to 5 days for a response to the first request before submitting a second request. Another 3 days is usually allowed for a response to the second request.
If the second request is not answered, the legal team has determined that a non-response is equivalent to a denial.