This is the first time in the program that I found the lesson much more difficult that it needed to be. We could have been taught in the following way: a date followed by the month takes an article - this is the only time (il tre aprile) if the name of the day is given - no article (lundi) for on Monday if the name of the day is given followed by a date - no article anywhere (domenica cinque luglio)
Anyway, it was much simpler than the lesson once I watched the tutorial a few times, wrote everything down . . .