In an ideal world, the 30 days currently prescribed would be enough time to respond to a relatively simple request, one that doesn't involve a mountain of records from a particular department. I'm talking about a clearly laid out request dealing with a specific topic. Whether they were 30 business days or calendar days would have to be determined.
Keep in mind that 70% of requests are answered within the prescribed 30 days, but a request for more time counts as a response. I think that's a good standard.
Personally, I'd like the time frame to be a bit less rigid, so that the 30 days were working days. Hopefully, more people could obtain the records they had requested or receive an extension request within that time frame. Ideally, the requester would receive a response within 30 working days.