Best way to build a Pseudo or Real Trending List

I am wondering how to implement a Trending posts list and was curious if anybody has any ideas about how to implement one.

More specifically, how could I go about trying to monitor what is trending and update the list accordingly. The only real method that I came up with is to:

• Go to the date a week back (Day-X) from the current date (Day-Y) and look at how many up votes a post (created on the Day-X) has accumulated up to Day-Y.
• Compare the up votes accumulated by every post from the previous step.
• Rank the posts (by highest upvotes accumulated from Day-X to Day-Y) and display them in a list for the entire day.

I feel as though this could be a sufficient enough method to present the users with trending posts every day, but I feel as though this method is pretty simplistic and only achieves a pseudo sense of trends.

Any comments, ideas, suggestions on how to go about this implementation would be very appreciated.