25. A computer program product according to claim 21 , further comprising program code instructions configured to: identify another time period to be described linguistically; and determine a descriptor that is defined by another temporal reference frame of the one or more temporal reference frames.
25. A computer program product according to claim 21 , further comprising program code instructions configured to: identify another time period to be described linguistically; and determine a descriptor that is defined by another temporal reference frame of the one or more temporal reference frames. 26. A computer program product according to claim 25 , wherein the descriptor for the another time period is different from the descriptor used for the time period.