In terms of the publication dates, this is complicated since our authors can publish at the click of a button, and can publish as many times as they want. A Leanpub author can publish dozens of times in a month, and can keep updating their book over the course of many years.
You can find the most recent publication date on each book's web page. We don't provide the first published date, since many of our books are published in-progress. The concept of "first published" means different things to different people, and many people consider it to be when a book was first completed.
We have never tracked that, since it was never important to us, and since some authors forget to update their book progress bar to be 100% when they actually complete their books...

Written by Peter Armstrong
Updated over a week ago