What is your target market doing this second? Sleeping in? Multi-tasking? Online shopping? Exercising? Working?
Asking "what is my target market doing right now?" should be the first question to answering "how to do they spend the entire day?".
You'll never change their behavior. And yes, many of their behaviors will have outliers. But once you figure out how the majority of your market spends their typical day you can figure out how, and especially when, to connect with them. The college kid sleeping in won't remember your awesome guerrilla campaign if it hits him anytime before 2pm. And your busy working mom is too consumed helping with homework and dinner to care what cool commercial just hit during the evening news.
Timing can be everything.