A hand-held device for measuring an analyte concentration in a sample of a body liquid includes a display means for displaying measured values; a measured-value storage for storing measured values; a measuring unit for generating measured values through measurements of the analyte concentration; a clock; a control unit for generating measured value datasets, each containing a measured value supplied by the measuring unit as well as the date and hour of the measurement by which the measured value was obtained, and for writing them into the measured-value storage; and operating elements that can be actuated by the user to set the clock, in which case the control unit will generate a time-correction dataset indicating the amount and direction of the setting effected. The control unit writes time-correction datasets into the measured-value storage so that a chronologically ordered sequence is generated containing time-correction datasets and measured value datasets.