A method for operating an electronic device includes: determining whether a battery remaining power amount of the electronic device is lower than or equal to a reference remaining power amount with which a power supply of the electronic device is maintained in a turned-on state until a time at which an alarm is set to be activated; and transmitting alarm information about the alarm to a second electronic device. The alarm information is information configured by an instruction prearranged between the electronic device and the second electronic device to enable the second electronic device to set an alarm function according to the alarm information automatically after reception of the alarm information.