title: NSDate between two given NSDates
body: <p>I am interested in creating a method to find if the current date falls between certain times on any given day. It is for a scheduling program, so I want to find what event is occurring at the current time. Every day has the same set of times: 820-900, 900-940, 940-1020, etc. Since this must be done on any given day I do not know how to create an NSDate with a certain time. I think this might be done with NSTimeInterval but I am not sure how to instantiate that.</p>