ding-hai day pillar

亥 is water, water controls fire, and 丁 is the yin fire above it. Yet the two stems usually listed in 亥 pull apart: 壬 is Direct Officer, the control, and 甲 is Direct Resource, wood that feeds fire. Both are yang against a yin day stem, which is why both come out as the direct kind.

Counted in reverse from 酉, 丁 reaches Conception at 亥. 丙 had that stage at 子, one branch further on, and the split is a direct result of the rule that runs yin stems backward. 三命通會 puts five days of 戊 into this branch and 淵海子平 does not, and from 丁 that extra stem would be Hurting Officer.

Earth on the Roof is again a poor match for the book. 三命通會 卷一 calls 丁亥 平原, a level plain, and says 喜火及木, pleased by fire and wood. Among the undefined labels that follow are four of the most favorable-sounding in the sixty: 天乙, Heavenly One; 福星, Fortune Star; 官贵, Official Honor; and 德合, Virtue Harmony.