A lot of people in this thread have given you good suggestions. What I keep seeing is people telling you to stop worrying about what your boss may be thinking, stop internalizing his feelings, stop guessing at his motivations and stop trying to get him to explain himself. It doesnt matter if he was mad at you or not. It doesnt matter if his energy or vibe made you feel like he was angry. He said he wasnt mad at you and that is all that matters. You do not need to be guessing what he really means or feels. You have to go with what he said. Yelling at him because you think he is really mad at you did not help things and will not make it easier in the future. He called you in early and you do not need to know why and he doesnt need to praise you for coming in early. You said you would, and did come in early and that is all that matters.