In legal proceedings from 16th century viceroyalty of Peru, indigenous witnesses identified themselves according to the convention of Spanish judicial system by name, place of residence and age. This last category often proved to be difficult. Witnesses claimed that they did not know their age or gave an approximate age using rounded decimal numbers. At the moment of the Spanish invasion, people in the Andes followed the progress of time during the year by observing the course of the sun and the lunar cycle, but they were not interested in measuring time spans beyond the year. The opposite is true for the Spanish invaders. The documents where the witnesses testified were dated precisely using counting years from a date in the distant past, the birth year of the founder of the Christian religion. But this precision in the written record perhaps distorts the reality of everyday Spanish practices. In daily life, Spaniards often measured time in a reference system similar to that used by the Andeans, dividing the past in relation to public events like a war or personal turning points like the birth of a child. In the administrative and legal area, official Spanish dating prevailed, and Andean people were forced to adapt to this novel practice. This paper intends to contrast the Andean and Spanish ways of measuring the past, but will also focus on the possible areas of overlap between both practices. Finally, it will be asked how Andeans reacted to and interacted with Spanish dating and time measuring. [ABSTRACT FROM AUTHOR]