I work 8-5, so yes, I realize apple is open during these hours. I know they are open until roughly 6 or 7pm. It's the after 5pm hours, and sat/sun hours I'm interested in. So I can plan my week.
An air gap for a dishwasher is a requirement set forth by local plumbing codes. It is a device designed to ensure water flows only in the right direction during the dishwasher cycle. As a dishwasher operates, hot water flows in from the sink's hot water connection.
There is a spout on the disposal that accepts the dishwasher drain hose. You will likely need an adapter like this to mount the hose: If there has never been a dishwasher hooked up to your garbage disposal, then you will have to open up the knock-out plug inside the spout.