The only utility in LabVIEW for measuring time as you indicate is the Profiler, which is under Tools>Advanced>Profile VIs (in LabVIEW 6).
Hope that helps.
Keep in mind that the profiler doesn't measure execution time of a VI, but the processing time. Any delays or waits are NOT included in the times reported by the Profiler. If you want the actual execution time, you have to measure it in the VI itself, or in a wrapper or calling VI.