Updating of map data in a navigation device

A communication navigation system is provided with a communication center apparatus (3x) and a communication terminal apparatus (5x, 5y) (5x, 5y) for transmitting/receiving information via a communication network (1x). The communication center apparatus includes a database (302) for storing data to be updated to the latest version, and a center side controlling device (301) for transmitting data in response to an updating request. The communication terminal apparatus includes a saving device (503) for saving data and the corresponding time and date information indicating the saving time and date of the data, and a terminal side controlling device (501x, 501y) for transmitting the updating request for transmitting the data over a predetermined period starting from the saving time and date, and updating the data by means of data transmitted in response to the updating request.