1. A method of translating expression using a computer having a processor and a data store, the method comprising: executing on the processor instructions that cause the computer to, upon receiving an expression: apply to the expression a temporal translation grammar comprising: at least one recognition rule respectively identifying a temporal element of the expression; at least one normalization rule respectively normalizing a temporal element of the expression to a normalized temporal element; and at least one translation rule respectively translating a normalized temporal element into a date.