Why isn't 24 hour time included in Y3 when it is part of the Y3 PoS?
When the 2014 National Curriculum was introduced, some degree of flexibility between year groups was encouraged. Y1/2 are linked and so are Y3/4 and Y5/6. So if a child had not understood a particular concept or skill introduced in, for example, Y5, the topic could be left until Y6 when it could be taught again with the child assessed at that point for understanding.