Qi Men Dun Jia, 奇门遁甲, military divination, 9-palace 3-pan oracle, Chinese strategy divination, heaven door earth door human door, 八门九星八神, 8 doors 9 stars 8 gods. Compute the Qi Men Dun Jia chart (9-palace with stars/doors/gods) for a given datetime, used for strategic decision making.