Accuracy at normal temperature  ±15 seconds a month Timekeeping Hour, minites, seconds, p.m.(P), year, month, day, day of the week Time format : 12-hour and 24-hour Calendar system : Full Auto-calendar pre-programmed from the year 2000 to 2099  Home City code (can be assigned one of 48 city codes) Standard Time / Daylight Saving Time (summer time) Diving FunctionsDive time measurement unit : 1 second Dive time measurement range : 23:59'59" (24 hours) Dive interval time measurement unit : 1 minute Dive interval time measurement range : 47:59' (48 hours) Dive records : 10 (Dive start month, day, and time, dive time, dive interval time) Tide / Moon DataMoon phase indicator for specific date Tide level for specific date and time High tide time adjustment Moon phase reversal World Time48 cities (31 time zones) Daylight Saving Time / Standard Time Alarms5 daily alarms (four one-time alarms; one snooze alarm) Hourly Time Signal StopwatchMeasuring unit : 1/100 second Measuring capacity : 23:59'59.99" Measuring modes : Elapsed time, split time, two finishes Countdown TimerMeasuring unit : 1 second Input range : 1 minute to 24 hours (1-minute increments and 1-hour increments) IlluminationEL(electro-luminescent panel) Full Auto Light Switch Selectable illumination duration OtherButton operation tone on/off Power SupplySolar panel and one rechargeable battery Approximate battery operating time : 10 months (from full charge to Level 4)