Certain Divisions, and the endcaps that go with them, go on certain days. I believe it varies ever so slightly depending on what region you're in as to what the exact daily schedule is, it used to anyway.
It won't take you long to catch on. If you look at your workload and Entertainment and Electronics are in there, you scan those endcaps that day. If you see Stationary, you scan those endcaps, and so on.
Be patient and give it some time, you'll be fine.