Important notice of software update notification for customers who purchased SATELLITE WAVE GPS F990/F950 model.
An unexpected phenomenon is confirmed for models with Caliber F990/F950. This phenomenon will occur if the result of “automatic leap second reception* ” is failed. While the watch is exposed under strong light in the daytime, this reception repeatedly activates until the reception result is successful. As a result, the battery may run out faster than expected.
Even this phenomenon will not affect the displayed time of watch or make the watch stop shortly, you are highly recommended to have the software updated so it can be used with confidence.
Please kindly contact the nearest CITIZEN Service Center if your watch model, case number and serial number are satisfied with the applicable scope in this notice.
*Automatic leap second reception
An automatic function that receiving leap second signal only takes place in June and December every year. The leap second signal is transmitted every 12 minutes, the reception result varies depending on the reception timing and reception environment.
How to determine the case number and serial number
Applicable Case Number and Serial Number
Applicable Case Number
Applicable Serial Number (*First 3 digits)
871******, 881******, 891******, 8O1******, 8N1******, 8D1******, 911******
*If the identification dot mark is shown, the software of your watch has been updated and it’s unnecessary to update the software again.