5. The method of claim 1 wherein the canonicalized format is selected from a group consisting of a canonical format to support specific date querying, a canonical format to support hierarchical querying, a canonical format to support range date querying, and a canonical format to support proximity date querying, wherein hierarchical date querying comprises querying for documents with a month, a month and year, or a year.
6. The method of claim 5 wherein the canonical format to support proximity date querying further comprises incorporating the location and span of the date occurrence, wherein the span comprises a count of the number of tokens in a date or in a phrase.