If you use the TwentyTen or TwentyEleven themes, there is a section in the functions.php script that allows you to remove the date from the comments. It is an override for the core file code that Will found. Making the change in the theme files is a much better way to go than changing it in the core files. The code looks almost identical to Will's core file example.
Be aware that if you allow comments, that plugin does not change the dates for the comments. Part of the issue here is that Google may be using comment dates to 1) determine freshness, 2) use the dates against the site if the dates are getting old.
Originally Posted by iowadawg
There may be some validity to that theory. Traffic went down for my older sites that use dates on posts and comments. Traffic went up for older sites that do not use post dates or comments. I am currently experimenting with a couple of sites that use post dates and comments by removing both the post dates and the comment dates.
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -- Benjamin Franklin