On the Timekeeping Mode setting screen, each press of B switches items in the sequence below.

Time offset
↓
Summer time
↓
12/24-hour timekeeping display
↓
Second
↓
Hour
↓
Minute
↓
Year
↓
Month
↓
Day
↓
Operation tone ON/OFF
↓
Illumination duration
↓
Alarmtimer alert method
↓
Power saving
↓
Return to time offset