At 4 weeks old, his attention span is very limited and so is his activity capacity. Lying on his back looking at black and white cards, because he is still unable to focus on long distances. Looking at mom's face, having his diaper changed and being talked to. If your baby is clearly tired and you are interpreting him correctly, then that is what the book is about. It isn't about strict deadlines.
Times are approximate.
It was never my intention for a mom to read this book and stick strictly to the times. The whole concept and my philosophy is based on respect and interpreting your baby's needs. So please use your instincts and the philosophy in the book, rather than the times. If, however, this book doesn't apply, or you feel this book isn't for you, then don't use it. It was never my intention when I wrote the book, for parents to interpret it to mean that they had to stick to strict schedules and times.