A method of operating a glucose test meter is provided. The method can be achieved by storing a plurality of glucose readings to a first memory of the test meter, each of the glucose readings having a time stamp and an order index, the time stamp comprising a date and a time when the glucose reading was performed, the order index indicating an order in which the plurality of glucose readings was saved to the first memory； determining whether successively saved glucose readings have time stamps in chronological order consistent with the order index； and indicating that the date and the time setting in the test meter is incorrect if there are successively saved glucose readings having time stamps inconsistent with the order index.
