TIME MANAGEMENT DEVICE AND TIME MANAGEMENT METHOD

摘要

There are provided a time management device and a time management method for reducing the chance for intentional false modification by a third person. In order to achieve this object, the time management device includes: external time acquisition means for acquiring external time within a predetermined time width; local clock means for outputting the self-running time; and time difference judgment means for calculating a difference between the external time acquired by the external time acquisition means and the self-running time output by the local clock means and setting the external time on the local clock means if the difference is smaller than a predetermined value but not setting the external time on the local clock means if the difference is equal to or greater than the predetermined value.