춘분을 기점으로 낮의 길이가 밤보다 점점 길어지기 때문에, 낮에 부지런히 움직여야 건강을 지킬 수 있다고 본 것이다.
Starting from the vernal equinox, the length of the day becomes longer than that of the night, so it is believed that you may keep your health by moving diligently during the day.