A display device including a used interface module configured to receive first time source data from a user; a broadcast service module configured to receive a broadcast signal; a communication module configured to perform data communication with a network time protocol (NTP) server, a memory configured to store the plurality of time source data; and a controller configured to extract at least one of first time source data extracted from a setting application, second time source data extracted from the broadcast service module, third time source data extracted from the NTP server and set a time of an application in accordance with a predetermined priority order based on the extracted time source data.