OK I've got the code that I want!
I've gone with the TIMEDATE format. From what I've read (thanks for the links) it seems to be the better one to go with. In regards to this intention:
I've read the MySQL Date and Time functions (thanks for the link obsidian) and have found the MySQL functions to be extremely valuable!!
For those interested, here's my SQL statement:
$query = "
SELECT title, body, author, authorID, publishedDate, categoryID, categories.name AS category, subCategoryID, subCategories.name AS subCategory, articles.genreID, genre, DATEDIFF(NOW(), publishedDate) AS dateDifference, DATE_FORMAT(articles.publishedDate, '%h %i %p') AS pubTime, DATE_FORMAT(articles.publishedDate, '%D %M %Y') AS pubDate
FROM articles
LEFT JOIN categories
ON articles.categoryID = categories.catID
LEFT JOIN subCategories
ON articles.subCategoryID = subCategories.subCatID
LEFT JOIN genres
ON articles.genreID = genres.genreID
WHERE articles.articleID = ". $articleID
From that I get a table that has 3 appended columns: dateDifference, pubTime and pubDate. With PHP I can manipulate the output like this:
$output = "Submitted by ". $row['author'] ." ";
if ($row['dateDiff'])
{ $output .= "on ". $row['pubDate']; }
else
{ $output .= "at ". $row['pubTime']; }
echo $output .".";
So thanks to obsidian and Zaid for your help!