The movement of your watch needs to be maintained at regular intervals. Changes in the viscosity of the oil (resulting in the oil drying out after a certain time) may generate friction and thus affect the precision of the mechanism, causing it to run fast or slow or to stop completely.
If your watch is noticeably fast or slow, the movement may need to be serviced for this reason. We recommend you to have the movement of your watch checked once every five years by a Cartier-authorized After-Sales Service. If your watch has not been worn for several months, you may need to wear it for several days before it regains its accuracy.