The Hero of Gettysburg
Lewiston Journal September 1, 1900

In this account of Petersburg Chamberlain gives the time of his second charge as 1:00, however in his written account he records it as 3:00.* It is likely in this interview without any notes in front of him he did not remember the time correctly. The Official Reports also indicate it was a 3 o'clock attack.
*Smith, Diane. Chamberlain at Petersburg. pg 58
Thanks to Diane Monroe Smith for finding this article for her book Chamberlain at Petersburg