Button operation:Press the button , the time show ,thenhold on the button more than 3 seconds until the hour change, thenlose your hand andpress the button one by one time until get your right local hour. You can use the same way to press the button again and don't move until get the minute change and then loss it ,press the button one by one time to get the right minute , You can do the same way to get the right date and month .