The DC Animated Universe timeline that I devised consists of the history of Gods and Monsters, where the Justice League: Gods and Monsters franchise takes place in. There is the Justice League: Gods and Monsters movie, the Justice League: Gods and Monsters Chronicles season one and season two shortform series, and the Justice League: Gods and Monsters six issue comic book mini series.
However, please note that this timeline is unofficial. That is, this timeline is created from my own personal observations and research. In order to make sure that this timeline maintains it consistency and validity, I had to incorporate many assumptions and constraints.
An assumption is easy enough to understand. I take a vague statement and add my own thoughts on what that means. For example, in "Genesis" Part Three, Steve Trevor is introduced as a Colonel on page 25. In the movie, Silas Stone's email lists him as a General. I assume that between "Genesis" and the movie, Trevor was promoted.
A constraint is something, in this case fact, that is binding and can not be modified. For example, in "The Dream", it is shown on page one it is July 1962.
With that said, here is the The Gods and Monsters Timeline.