[Highway Star]

I am curious about how this feature is set up. I am used to clicking that link and seeing a day's worth of threads that others have posted in. Here, sometimes it shows me quite a few and other times, only one or two, maybe after I have remained logged in but idle for a while. Is it strictly based on how many posts are made between each time I click the "New Posts" button? Is there a way to show all posts over the last day? Again, just curious...thanks.