Addendum

And don't feel forced to include, for instance, goats just because somebody mentions the year of the goat. That can be another tantalizing mystery.

Take the Easy Way Out

You want to include astrological matters in your fantasy story but aren't sure about coming up with your own constellations, processions, retrogradery, interpretations, and so on? Don't! Just use ours! Let readers debate whether that means it's post-apocalyptic. They love debating.

Addendum

I realize nobody uses hep anymore, but by the time science fiction happens, it might be back.

Future Fields of Study

By the time your science fiction story happens, people probably will have gotten it together and realized we should talk about rock-science, star-science, and snake-science instead of those weirdo terms we use today. For one thing, those different endings are confusing. Who would know just from hearing it that astrology is the fake one? Furthermore, I don't think hepatologists are particularly hep, not to mention with it, though I could be mistaken.

Pioneer Concerns

Another historic day! Every day seemed historic, or rather, was historic. How could it not be in New Jericho, humanity's first city on another planet? The governor did a few stretches. He needed to be historically serious to deal with the momentous, era-defining task he had the unique opportunity to complete.
On his desk waited the first, no, the inaugural New Jericho survey. The colonists, chosen from a vast population by not only the examination board set up at the sponsors' request but also by their own daring personalities, had all been consulted as to the state of the city in every important facet. Beyond that, they were encouraged to write in the empty portion any items they believed to be essential for the city's prosperity that had been neglected to that point.
Governor Erle Drake sat himself down and read through the surveys, ebullient at first, then disconcerted, and at last positively discombobulated. "But . . . but . . ." His composure abandoned him just as he had left Earth. Dashing to the balcony, he yelled, "Who is it? Who thinks the most pressing business is . . . is . . . remaking astrological charts?"
"Me," a structural engineer passing below said.
"Same," concurred a nearby psychiatrist. "The stars are all different here, so, you know."
"I suppose!" Governor Drake clenched the railing and tried to expel the scorn from his words. "I suppose that next you would like us to establish a commission, for the purpose, of inventing, a creation myth for this planet! And its people!" The scorn was still there. "Oh, can we do that?" A crowd gathered below the capitol building.
"That sounds great!"
"I hope we get something more inspiring than a celestial egg."
"Can it have dragons in it?"
"Better be some incest. Not a proper creation myth without it."
"How about this for a start: once upon a time, matter was energy, and energy matter."
And so a commission was formed, and the governor lost a spoonful of enthusiasm. The next historic event corrected that deficiency, however. There was no shortage of those.
Finis

To See the Future Is to Conquer It

The astrologers claimed the world would change, that the heavens would treat them differently, and the great king listened. He thought, he mused, and he pondered till the gods spoke to him.
He commanded a great work. The cleverest designed it, the wealthiest funded it, and the strongest carried it out. For years blocks were cut, hauled, and set in place so that above the groaning plain rose the pyramid, the answer to the certain prophecy.
When the work was done, the great king himself ascended to the very apex. None of his counselors did he permit there to attend him. He waited, he waited, and he waited.
Then, at last, clouds gathered and for the first time gave the land snow. And the great king was the first of thousands to sled down the pyramid, which was so rad he had it written on pillars in order that all who read of his feat throughout the ages might know how totally sick it was.
Finis