Press the button three times to enter the time-setting mode. The seconds digits should start flashing.
Инструкция к часам Kenko kk-613d, Nako na ... - michael_1976 nako na613d user manual exclusive
Press once to enter stopwatch mode (display will show 0:00:00 ). Press D (Start) to begin timing. Press D (Start) again to stop/pause the timer. Press the button three times to enter the time-setting mode