The custom of eating dumplings on New Year's Eve is related to an ancient Chinese method of measuring time; in ancient China, each day was divided into twelve sections: the beginning of each day was called 'first time', which corresponds to the period from 11pm to 1am.
过年吃饺子的习俗和中国古代的计时法有关：中国古代把每一天分为十二个时段，每天开始是子时，相当于晚上11点到凌晨1点。