Well what I did was to click on the drop arrow besides "Fetch News" and select "Add or edit a custom news source".
Select the "Customize builtin recipe" button and then type in the name of the recipe "A List Apart". This will display the recipe.
Look for a line that reads
Code:
oldest_article = 120
and change it. For my test i changed the 120 to 365.
Click the save button and it's done!