When the Abbasids defeated the Umayyads, they eventually decided on founding a new capital city. Under Al Mansur they built the city of Baghdad, blending knowledge of astrology and urban planning to birth a city of wonder.

A thread on astrology and Baghdad -AAO

Al Mansur settled on Baghdad’s location in proximity to the old Sassanid cities & called upon Indian & Central Asian city-planners to build it round in the Persianate fashion, but in order to build a truly wondrous city he called upon the powers of astrology -AAO

He turn to the Persian Nawbakht and the Jewish astrologer, Mashallah ibn Athari. -AAO

Together they employed ikhtiyārāt, a type of astrology used to elect the most auspicious timing for an event.

Want to know the perfect day to get married, to sign a contract, or even to wage a war, ikhtiyārāt can provide the answer -AAO

Using ikhtiyārāt Nawbakht and Mashallah elected July 31 762 for the founding of Baghdad. The historian and contemporary astrologer, James Holden used the Persian Al Biruni's records to recreate the horoscope.

I’ve attached a contemporary version -AAO