Franklin

Mass Effect 2 & Mass Effect 3
A large moon, Franklin retains a trace atmosphere of carbon dioxide, but its desolate surface holds no signs of water or life. In order to defend Watson from the pirates of the Terminus Systems, Franklin is home to two Alliance spaceports and naval bases capable of fielding six fighter squadrons each and a classified number of interplanetary ballistic missiles. Mass effect fields keep the gravity in its installations at a comfortable level for long-term living.
 * 33 Earth Days (around Watson), 3.0 Earth Years (around Skepsis)