Could someone give a couple of examples for the points made in the section "Accounting for temporal data"?  Trying to understand the section.

1.  What do you mean by "accounting for" or "accommodating" temporal data?  Are you enforcing the expiration date/time of the data?

2.  In the first paragraph, "The base class can also contain properties suited for lists such as ListType and SortOrder.".....how would this help "account for" or "accommodate" the temporal data?

3.  I think a clearer idea of the problem of accounting for temporal data would also make it easier to make sense of the last 2 paragraphs in this section. 

Thanks