"Ji Ming" (鸡鸣), according to the "Ciyuan" dictionary, is defined as "a type of weapon." According to the "Cihai" dictionary, it is "the name of a chapter in the "Shijing" (Book of Songs) and the title of a song in the "Xianghe Ge" (Harmonious Songs). Another name for "ge" (戈, a kind of weapon)." Neither of these reference books provides an explanation for the meaning of "Ji Ming" in the context of the twelve hours. From a literal perspective, "Ji Ming" indeed means "the crowing of a rooster," but in the context of the twelve hours, it specifically refers to the period after midnight and before dawn, i.e., 1-3 AM, which is known as "Chou Shi" (丑时) in terms of the terrestrial branches. Chickens were praised by ancient Chinese people as "the time-keeping animal." In the "Han Shi Wai Zhuan" (External Records of the Han Poetry), chickens are praised as: "It does not miss the time to keep watch, this is loyalty." When the first light of dawn appears, roosters crow, and the morning arrives; people get up.

The second hour corresponds to the ox in the zodiac. As the saying goes: "Horses do not fatten without night grass," and cows are no different. Farmers use oxen for plowing fields, and feeding the ox well is a major task for farmers. During the second hour (1-3 AM), farmers would naturally rise to feed the ox. The connection between the ox and the second hour makes it known as "Chou Niu" (丑牛).