Spring Festival

Recently, my brother, Derek, asked me about the date of Chinese New Year (Spring Festival). Contrary to common belief, Chinese New Year is NOT the first day of the spring. Rather, it is the second (sometime, third, depended on wheter there is a leap month) new moon day after winter solstice (~12/22). The rule is set by Adam Schall (湯若望), a Jesuit priest. He helped to reformed the Chinese calendar during KangXi (康熙) time. Details can be found here.