The present invention provides a mobile equipment for non stationary use. The mobile equipment includes a real time clock (RTC) integrated in the mobile equipment for generating a real time information, a system time generator integrated in the mobile equipment for generating a system time information by adding an offset to the real time information given by the RTC, a non-volatile memory for the permanent storage of data and an input means for inputting instructions for changing the system time information. The possible changes of the system time information generated by the system time generator may be limited to a preset time range and the possible reset value of the RTC may be limited according to the data stored in the non-volatile memory.