This is a section printed daily in the Times (The London newspaper) detailing the day's Royal activities: who is receiving whom where, that sort of thing.

It is not clear who this is supposed to help, as if you were going to go and see the Queen, you'd probably plan in advance. I suspect that the major use anyone has of it is that as the Times is commonly archived, it becomes easy to know what the official Palace line was about who was doing what on that date.