The aim of this project is to review and expand upon the model proposed by Father Jose Domingo Duquesne de la Madrid (1745-1821) regarding the calendar of the ancient Muisca culture of the central Colombia. This model was dismissed by scholars in the late 19th century, calling it just a simple invention of a clergyman; however, a detailed analysis of Duquesnes work shows that his interpretation of the timekeeping system was based on information given to him by indigenous informers. Based on his work, we can be derive somewhat indirectly, some aspects of the calendar that apparently were not understood by the priest. This confirms that such a system was not his own invention. Ethnohistorical and archaeological evidence provide support for Duquesnes calendar model. Massive Muisca ceremonies described by 16th century Spanish chroniclers, is examined and; the occurrence of such ceremonies seem to match the astronomical cycle of conjunctions of the planets Jupiter and Saturn, wich also agrees with the 60-year span described by Duquesne as the Muisca Acrotom Century. Archaeological artifacts, such as a carved stone found in the village of Choachi (Cundinamarca) that shows numerical elements supports Duquesnes model that suggests this stone was a calendar calculation tool for Muisca priests.