[DanCooper]

The "dateAdded" and "dateModified" are stored as Unix-TimeStamp like "1550098296". It is not really readable value, that's the reason why the column can not be displayed via settings.
What you could do is to create a custom list that only displays entries from a certain date (converted with e.g. https://www.unixtimestamp.com/):

sql:
SELECT

  *

FROM

  movielist

WHERE

  dateModified > 1553548598