Chronomancy is the use of a divination method to determine the precise time for action.
Derived from the Greek chronos, time.
Chronomancy is the prediction of the best time to do something, the determination of lucky and unlucky days. It was especially popular in ancient China. Chronomancy is not a methods but a means to an end and thus can be achieved using various divination methods such as tarot reading or geomancy.
Chronomancy is also used in fiction but with a different meaning to refer magic involving supernatural manipulation of time.