PURPOSE: To facilitate the check of time and to improve the accuracy for setting the time by constituting this system for time correction in which one configuration element is a master and the other is a slave, executing periodically a time request from the master, and executing the check of an error and the correction request of an error.

CONSTITUTION: The system consisting of plural stations is formed as a master/ slave system consisting of one master station 1 (master) and other slave station (slave) for the time operation. Also, the time as the whole system is unified, based on the time of the master 1 as a reference. That is, the master 1 is provided with a master clock 4 which becomes the standard timepiece, a counter 6 for counting the number of times of a range check, etc., and executes a communication to the slave 2 through a circuit 3. In such a state, each slave 2 periodically informs the master 1 of its own time, and when the time of the slave 2 is in the outside of an allowable range of an error, the master 1 requests a time correction to the slave 2, based on its error value. In such a manner, the accuracy of time and the facility of a time check can be improved.