def date(col, comparator, date, args, block)
        comparator = '==' if comparator == '='
        operation = "Date.strptime(\"[value]\", \"#{date_format}\") #{comparator} " +
                    "Date.strptime(\"#{date}\", \"#{date_format}\")"
        pivot["#{comparator}#{date}"] = { col: col, operation: operation }
      end
def date(col, comparator, date, args, block)
        comparator = '==' if comparator == '='
        operation = "Date.strptime(\"[value]\", \"#{date_format}\") #{comparator} " +
                    "Date.strptime(\"#{date}\", \"#{date_format}\")"
        pivot["#{comparator}#{date}"] = { col: col, operation: operation }
      end
Adds a date filter