19. A computer readable storage medium as recited in claim 18 , wherein the contextual date information of the date request includes one or more word (s) arranged in a natural language.
19. A computer readable storage medium as recited in claim 18 , wherein the contextual date information of the date request includes one or more word (s) arranged in a natural language. 20. A computer readable storage medium as recited in claim 19 , wherein the contextual date information specifies a holiday.