The author of this manual is actually of the opinion that this chapter should not be started like the others. It should not be necessary to tell again that German grammar is a bit weird and that even the easiest things are made a bit complicated in German. When now talking about the time and date, one fact is that the German pronunciation of the time has nothing to do with the way it is written. Therefore, we can only present the facts and try to explain them in a clear way and hope for your understanding that history and many influences have created a quite complicated system of grammatical structures. Still, a lot of people have it as a mother tongue and you have made it so far in learning that you know what to expect: declination and other weird stuff.