Created vs. Published Date

I would like the Published Date to show on the blog instead of the Created Date. How do I change that setting? I looked all through all the settings and can't find where I can change it.

I would like to put all the blogs into the system on Monday but have them published on different days of the week. And I don't want people to know that they were created on Monday. I want it to look like they were created on the day they were published.

Can you help??

Thank you,