This is not a totally obvious function, since overflow must not occur, and microseconds are not required to be in the [0;100000[ range.
|startingSecond||the second corresponding to the starting moment.|
|startingMicrosecond||the microsecond corresponding to the starting moment.|
|stoppingSecond||the second corresponding to the stopping moment.|
|stoppingMicrosecond||the microsecond corresponding to the stopping moment.|
|SystemException||if the duration is strictly negative.|