US Patent 7966341 Estimating the date relevance of a query from query logs

Techniques are provided maintaining data that indicates for a plurality of query terms whether the plurality of query terms are date-qualified query terms. A query is received, and in response to receiving the query, the query is inspected to determine that the query contains a particular date-qualified query term. Then it is determined that the particular date-qualified query term has been associated with a plurality of dates, and it is determined which of the plurality of dates with which to associate the date-qualified query term for the query, based at least in part on the frequency with which each particular date of the plurality of dates has been associated with the particular date-qualified query term.