PURPOSE: To prevent an erroneous setting to a sounding memory by a system wherein a decision result on whether or not a time setting has been carried out is stored in the sounding memory, and a matter on whether "active" or "reactive" to take for actuation of a setting means is left depending on memory contents.

CONSTITUTION: A sounding time in a sounding memory M is decided with a decision means D, and a decision result that the sounding time has been set is stored in a decision result memory S3. Then, when contents of the memory S3 are transmitted to display memories S2, S3, the sounding time is set after coincidence with contents representing a colon to detach an hour digit and a minute digit. Where there is no sounding time set in the memory M, a blocking function of AND circuit A according to the memory S3 comes to stop, therefore a time can be set from a time-keeper memory to the memory M by actuation of a setting control means S1. Furthermore, a setting of the time set in the memories S2, S3 is carried out to the sounding memory by actuation of the means S1. Where the time has been set in the memory M once, no change in set time in the memory M will occur in actuation of the means S.