When the watch is unable to adjust its time in accordance with a calibration signal for some reason, average timekeeping accuracy is within ±15 seconds per month.
Note that an internal decoding process the watch performs after it receives a signal may cause the time setting to be slightly off (by less than one second).
Time signal reception is not possible when any one of the conditions below exists.
While battery power is low
While the watch is in the Stopwatch Mode, Timer Mode, or Alarm Mode
In Power Saving Level 2
Timer countdown operation in progress
While auto time adjustment is disabled
While the Home City setting is one where time signal reception is not possible
While the watch is outside the time signal reception range
If the receive operation is successful, the time and day settings will be adjusted automatically in accordance with the Home City and summer time settings. Summer time will not be applied correctly in the cases described below.
When the summer time start date and time, end date and time, or other rules are changed by authorities
If your watch is connected with a phone, settings must be configured so CASIO WATCHES can acquire location information. Even if you are in an area that is within the reception range of a time signal, reception will not be performed if settings are configured in a way that makes signal reception impossible.
As of July 2018, China does not observe summer time. If China starts to observe summer time in the future, the time displayed by the watch for China may not be correct.
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