《宋书·志·卷十六》
我认真查考晋武帝时郊祀是在二月，晋元帝时里祀祭天是在三月。
谨寻晋武郊以二月，晋元禋以三月。
I carefully examined that the suburban sacrifice of Emperor Wu of Jin Dynasty was in February, and the sacrifice to heaven of Emperor Yuan of Jin Dynasty was in March.