Astrology?
No. We know that we are not ruled by the stars and planets. But the celestial bodies are markers for dates and events - esp. in the ancient world. So when men of old would prophesy, they would use familiar markers that others would understand.
And no, it’s not astrology. Not in the sense you mean. Someone divining your horoscope. But in the old way, you could count time not just by the short cycles of celestial bodies, but you can pin point time in the future (for prophesy) by speaking to their alignments. \