The problem may be caused by some preset DAB or RDS stations with time signal broadcast. These RDS stations will broadcast time with a regular frequency and the device will auto synchronize the clock time with these stations. In this case the accuracy of the clock time depends on the accuracy of the time signals. If you don't like the clock time is auto changed, just turn off the clock time synchronization function by following: In RADIO mode, press and hold MENU for around 2 seconds to turn off. You can turn on clock synchronization function by pressing and holding the MENU button again for around 2 seconds. Term Explanation: RDS - The feature RDS (Radio Data System) is a service that allows FM stations to send additional information along with the regular FM radio signal. When you are receiving an RDS station, and the station name are displayed. DAB - DAB (Digital Audio Broadcasting) is, on top of FM analog transmission, a new way of broadcasting radio via a network of terrestrial transmitters. It provides listeners with more choices and information delivered in crystal clear, crackle-free sound quality. The technology allows the receiver to lock on to the strongest signal it can be find. With DAB digital stations there are no frequencies to remember, and sets are tuned by station name, so there is no returning on the move.