Why is dawn a common image in poetry?

Ai Qing wrote Dawn on the morning of May 23, 1937/kloc-0. The author compared "I greet the dawn" to "a girl who came from the other side of the field in a hurry", which vividly reflected the author's longing for the dawn and expressed the author's love and praise for the dawn.

He also mentioned that "the dawn brought him freedom and enthusiasm for work". Dawn seems to be the author's bowl of chicken soup, a driving force, a friend who has been encouraging him, giving the author strength and courage. Therefore, the author does not want the dawn to disappear. The disappearance of dawn will remind the author of terrible things, which shows the author's love and cherish for dawn. Dawn is very important to the author.

Dawn is dawn, dawn. It is the sign and symbol of the next day, and it seems to tell people hopefully that the next day has arrived, so go and meet it. It is such a hope that the author has different likes and expectations for it. For reference.