code: def previous_blocks(self, quantity=-1):
          
          blocks = (EighthBlock.objects.get_blocks_this_year().order_by(
              "-date", "-block_letter").filter(Q(date__lt=self.date) | (Q(date=self.date) & Q(block_letter__lt=self.block_letter))))
          if quantity == -1:
              return reversed(blocks)
          return reversed(blocks[:quantity])
docs: Get the previous blocks in order.