A method is provided for determining a master time signal, in particular in a vehicle. The method includes the acts of: a) receiving at least one first server time signal from a first time server; b) receiving at least one second server time signal from a second time server; c) comparing the first server time signal with the second server time signal in order to determine at least one first time difference; d) storing the first time difference; e) determining an availability of the first server time signal and/or of the second server time signal; f) using the stored first time difference to determine the master time signal at least if at least one of the server time signals is not available.