BAMPFA-79: Some grammar reorganization.
BAMPFA-79: More grammar reorganization.
BAMPFA-79: Handle year ranges.
BAMPFA-79: More grammar cleanup, and add support for date ranges.
BAMPFA-79: Fix StructuredDate equals not comparing latest dates.
BAMPFA-79: Add support for month ranges.
BAMPFA-79: Add support for season and quarter years.