The movement of your watch needs to be cleaned periodically. Changes in the viscosity of the oil (oil becomes dry after a certain amount of time) can cause rubbing and thus damage to the precision of the mechanism (slow, fast, stop).
If your watch is running significantly slow or fast, it may be necessary to have the movement checked.
We recommend that you have the movement of your watch checked every five years by a Cartier approved After-Sales Service centre to keep it in perfect working order. If your watch has not been used for several months, you will have to let it function for a few days before its original precision is re-established.