[Geee]

I've implemented this in one project with the addition that allows entries to 'keep afloat', or resurface if they are suddenly voted a lot. So, the behavior is more like what you would see in 'Popular now' list on Youtube, without having to compute running averages.

The way I did it was to update the post time with fractional of the difference of the old timestamp and current time, i.e:

    post_time += (current_time - post_time)/10

That way, if the post is really old, voting gives a decent boost to it, but if it's more recent, it has negligible effect.