Abstract: Presentation and processing of uncertain temporal which contains semantics are important issues in uncertain temporal information processing and natural language processing. Uncertain temporal span is an important part of uncertain temporal, however, the uncertain semantics is the root of uncertainty. This paper proposes the idea of converting the uncertain semantics to the forms existing in neighborhoods or intervals that could be calculated and described on the granularity level. At the same time, a tuple model was given to render uncertain temporal span to join the calculation. Then a temporal rough set is suggested to divide the certain or uncertain elements of temporal span according to lower approximation and upper approximation. Finally, the approximate accuracy calculation of uncertain temporal span is presented.

Key words: uncertain temporal span; semantic; temporal granularity; temporal rough set; approximation calculations