Chinese date’s are known as a warm food. (People believe that all kinds of food have characteristics -warm or cold, in oriental culture.) So it makes you relax and warms you up (good for insomnia and cold body sense) . It is often used with ginseng as a roborant (a strengthening food) for example in Ginseng tea or samgyetang (Korean ginseng chicken soup).
This is a picture of dried Chinese dates I bought the other day.
I found a good description about Chinese dates from Wikipedia. So you can read more about them.