That's a great question. My feeling is yes but I can't think of anything in particular that proves this. Given that no Transformers have been shown to be freaking out when it got dark on Earth I think they know of the concept of day and night. For most of the Marvel Comics Cybertron didn't orbit a star so they wouldn't have days and nights. Cybertron's often shown with a dark night sky which maybe could be explained by a similar atmosphere to Earth (?) except that humans are able to wonder around and breath normally on the planet.