Abstract This paper offers a study of Mullā Farīd and Mullā Ṭayyib, two astronomers active in several North Indian courts in the first half of the seventeenth century. The lives and works of these two brothers illustrate the central role of mathematical astronomy and astrology in the science of the time and its use by Indian Muslim nobility. They also document the familiarity of Indian Muslim scholars with Indic astrology and its practice in Muslim milieux. Mathematical astronomy was very much alive in seventeenth-century Mughal India, and Persian-writing scholars were commenting and revising the astronomical data and mathematics transmitted from the Maragha and Samarqand schools of astronomy. Their intellectual activities are also better understood in the context of the avid interest in occult sciences cultivated by early modern Persianate societies, and more particularly by the Mughal court. Mathematical astronomy was nurtured for the precise purpose of casting horoscopes and creating astrological almanacs. Astrological practices in North-Indian courts, including Delhi, the Mughal imperial capital, were evidently mixed and flavoured with elements from both Islamicate and Indic traditions. Knowledge was widely shared across languages and scientific interests went well beyond religious denominations. Crucially too, the exchange between the Persian and the Sanskrit scholastic worlds was sponsored by Mughal patrons and resulted in scientific translations from one language to the other. A closer reading of Mullā Farīd and Mullā Ṭayyib’s Persian works allows us to see that besides their more classical astronomical works, the two brothers shared a common interest in Indic methods of prognostication, in particular muhūrtaśāstra , the science of electing an auspicious moment to perform a certain action. In this paper, we elucidate an intricate dossier on the “ bust hours,” an ancient prognostication method popular with Islamicate astrologers. Identified by Islamicate scholars as coming ultimately from India, the source of many features of Islamicate astrology, these bust hours were reinterpreted on Indian soil by Mullā Farīd and Mullā Ṭayyib in light of their first-hand knowledge of muhūrtaśāstra . In this manner, these bust hours came back full circle to the original Indian prognostication practices.