PURPOSE: To clearly indicate a reference zone to a user, by a method wherein time correction is brought to a prohibitive state when a selected zone is not coincided with the reference zone and the display of a month and a date of the reference zone is performed to a display part in the case of coincidence while the time correction enabling state is formed.

CONSTITUTION: When a change-over means 9 is set so as to output the zone code 01110 of New York as a reference zone and changed over to Tokyo, a zone code 00000 is stored in a code memory 12. A comparison circuit 14 detects the non-coincidence of the content 01110 of an initial code memory 10 and the output 00000 of the change-over means 9 to prohibit a correction circuit 17 from transferring a correction mode. When the change-over means 9 is changed over to New York, a comparison circuit 14 detects the coincidence with the initial code to issue output E3 as coincidence output 1 and a display change-over circuit 6 outputs the month and date data of a clock circuit 3 to a display part 7 to perform display while a control circuit 8 brings a control signal C6 to 1 to enable that the correction circuit 17 is transferred to the correction mode and it is clearly exhibited to a user that the reference zone is New York.