I'm new to this, but logic would dictate that you need to target your intended audience as skilfully as possible, which means you'd want to end up at the top of the "new" list right at the time when the most of your potential visitors are hitting the site.
In addition, I'd keep in mind the fact that each broad group of topics will definitely have it's own sphere of surfers. For example, if you are publishing a video game hub, you'd want to target high-schoolers and young adults, so you'd publish around 4-5 pm when they get home from school and then maybe around 8-9 when most young adults that play get home from their part-time jobs. For child care advice, you're targeting moms mostly, so you would probably hit early or late morning, or whenever moms surf the net most. Market research would be crucial here, obviously.
So it depends on the topic, but that is because it depends on your target audience. Know your audience and you'll know your path to popularity.