Method for determining a period

A method for determining a vehicle time in a vehicle, comprising:

• operating the vehicle based on the vehicle time which is advanced by an oscillator,
• receiving a quantity of time information from a plurality of time sources external to the vehicle, wherein a respective time source confidence measure is assigned to each of the plurality of time sources,
• determining a respective deviation between the time information of each of the plurality of time sources,
• establishing a total confidence measure based on the time source confidence measures and the respective deviation between the time information of each of the plurality of time sources,
• maintaining the vehicle time based on the oscillator when the total confidence measure is less than a confidence threshold, and suspending use of the vehicle time by an application executed by the vehicle, and
• updating the vehicle time based on the time information of each of the plurality of time sources when the total confidence measure is greater than the confidence threshold, and resuming use of the updated vehicle time by the application executed by the vehicle.