An IMDb user can see when they've added a title (film) or name (person) to a list and when they've updated the information for a list item in the list. I will use one of my list that will illustrate how to check this.
This is the default view of my list:
http://www.imdb.com/list/nIqDiPOOkJY/
If you click the third box next to view, you will get the contact view.
http://www.imdb.com/list/nIqDiPOOkJY/...
The compact view includes the columns:Title, Year, Type, #Ratings and Date. The Date column shows the date you added the film.
You can also edit your list and change your list settings:
* Default sort order
* Default list view
If you wish to know when you changed information for a film, you can export your list. The export list link is at the bottom of the page. Exporting a list produces a comma separated file (csv) that you can read into Microsoft Excel, Open Office or Google Docs. The data fields are
position, const, created, modified, description, Title, Title type, Directors, You rated, IMDb Rating, Runtime (mins), Year, Genres, Num. Votes, Release Date (month/day/year) and URL.
For more information see:
Frequently Asked Questions about Lists
