[Photo/Xinhua]

Swallows fly north

The ancient Chinese people divided the fifteen days of the Spring Equinox into three "hou's," or five-day parts. As the old saying goes, swallows fly back to the North in the first hou; thunder cracks the sky in the second hou; lightning occurs frequently in the third hou, which vividly reveals the climate feature during the Spring Equinox.