Ah, good question. I can see that you are actually trying to apply Tiki! Please see my post titled Noble warriors of Tiki rollout development UNITE...
And here's a hack. In tiki-blog_rss.php (NOT tiki blogs_rss.php), find the line:
Change this to:
And you'll get the blog's title instead of the date in RSS output. Note: you must enable blog titles (and each blog post must have a title, of course).