This book investigates the historical development and socio-political context of the ancient calendrical systems specific to the Thar Desert region. Anthony Gordon O'Brien utilizes his expertise in South Asian history to synthesize complex chronological data, focusing on the Bhattika, Laukika, and Sindh eras. The work argues that these systems were not merely technical tools but were deeply embedded in the shifting political and military landscapes of the region.

Experts in South Asian epigraphy and regional history recognize this work as a specialized contribution to the study of Rajasthan and Sindh. Readers frequently note the technical density of the prose, which serves as a foundational resource for scholars examining ancient Indian chronology.