If you do not use the camera for a long time, the built-in rechargeable battery gets discharged and time settings may be cleared. In this case, when you turn on the camera, the CLOCK SET screen appears. Please set the date and time again.
To charge the built-in rechargeable battery, connect the camera to a wall outlet with an AC adaptor, or attach a fully-charged battery, and then leave it off for more than 24 hours.
NOTE: Even if the pre-installed rechargeable battery is not charged, the camera operation will not be affected as long as you are not recording the date or using a GPS function (if applicable).