What do I do if I See the Incorrect Dates for Blog Posts?

First, in the liquid template for your Blog and Article pages (which are listed as blog.liquid and article.liquid, respectively) you need to change the variable { { article.created_at } } to { { article.published_at } }. If you haven't worked with the liquid templates for your blog before, you can find them in your Store Admin section under Themes > Template Editor.

If this does not fix the problem, it is likely that the RSS feed you supplied to BlogFeeder does not contain the publish date for your posts. Check the RSS feed to see if each post actually has the publish date property. If you're original post does not have this date, then BlogFeeder will not be able to import it and will set the import date as the publish date.