def weekdays
      selected = @weekdays.select { |_day, day_selected| day_selected }
      # Ruby 1.8 returns an array for Hash#select and loses order
      return selected.keys if selected.is_a?(Hash)
      selected.map(&:first).sort_by { |v| WEEKDAY_KEYS.index(v) }
    end
def weekdays
      selected = @weekdays.select { |_day, day_selected| day_selected }
      # Ruby 1.8 returns an array for Hash#select and loses order
      return selected.keys if selected.is_a?(Hash)
      selected.map(&:first).sort_by { |v| WEEKDAY_KEYS.index(v) }
    end
Returns array of weekday selected
 e.g. [:sun, :sat]