《晋书·志·第十二章》
二月的管名字叫夹钟是因为夹就是佐，说的是遣时万物还没有完全长出来，阴德辅佐阳气而使万物出生。
二月之管名为夹钟者，夹，佐也，谓时物尚未尽出，阴德佐阳而出物也。
The reason why February is called "Jianzhong" is because "Jian" means assistant, which means that all things in the time have not yet fully grown, and Yin virtue assists Yang Qi and gives birth to all things.