Currently, you can only view the most liked images in one of 2 time frames: the default "past 24 hours" (mislabeled as it seems to only count from last midnight to the current time) and all time. Week, month, and year options are obvious candidates, but I say make it as granular as the user chooses if that's not too difficult. For example, say I love colored horses and long for the days they reigned supreme on KYM, but only before season 3. I should be able to view the most liked images from October 10, 2010 to November 10, 2012. In any case, any more choice would be preferable to just today or the site's whole lifetime.
This just occurred to me, but if this is a search operator I don't know about, please tell me (if not, it would be a good one). The custom range could be a search operator while week, month, and year ranges could be under the "Most Liked" tab (where "All Time" currently sits alone).
[This obviously can apply to most commented, favorited, viewed, least liked, and videos altogether (which lack "least liked" for some reason), but I only used most liked images for simplicity and I assume it's the most popular.]