OK, it appears we're talking about Chapter 10 of the tutorial (on agents) and specifically the section on pages 72-74.
From your screen grab, your agent is finding notes (17 - as shown bottom right of the grab).
It looks like the tutorial has a typo. The action, using the
date() is using the parameters in the wrong order. It should be in the form
date(year,month,day,[hour,min]) as explained in more detain here.
Thus the action in your file (and the tutorial PDF!) should be:
Testing this (in a different test file) I observed notes with no $PublicationYear got a $StartDate of "01/01/1, 00:00" which is clearly not desirable, so a real-world version of the above might better be:
Of course, in the tutorial context the notes of interest do have a $PublicationYear, and the aim is not to over-complicate!
I hope that helps - do ask if not!