戌 holds seven to nine in the evening and, in the year, the stretch after the frosts, with autumn ending and everything going into store. It's earth, and among the four storehouses it's fire's: what remains of summer's burning is kept here.
So 戌's function is storing and guarding: the harvest is in, and now someone has to watch it. The dog fits, and its loyalty is the personality version of the function — seeing the risk first, because the position is staying alert while everyone else relaxes.
Where 戌 sits in a chart, that area needs you to see it through, and you tend to be the one who thought of the worst case first. 戌 carries 地網, the earthly net, opposite 辰's heavenly one: both say protection can become confinement, one arriving from above and one from below.
