how to calm when someone is angry

Well I am completely confused. I tried all ways to make some one feel better to calm down their anger. Do i really dont know how to calm a person. Simple thing i did was to give time. Today after week, i see its the same level. Not even a small amount of anger is lost. Really i am clueless how can i calm down. I do really lack soft skills. I really dont know how to change mood of person. All i can do is ride with the feeling, not change. How sad. :(