django：daterangefield属性错误

Question

我收到此错误'int'对象在跟踪中没有属性'days'，突出显示camp.save()

我的模特课：

class Campaign(models.Model):
    time_to_next = DateTimeRangeField()
    rank = models.PositiveIntegerField()
    address = models.ForeignKey(Address)
    description = models.CharField(max_length = 200)
    display = models.BooleanField()
    date_created = models.DateField(auto_now_add=True)
    url = models.URLField()
    current_promotion = models.ForeignKey(Promotion, related_name="campaign_current_promotion")
    promotions = models.ManyToManyField(Promotion)
    enabled = models.BooleanField()

我的观点：

camp = campaign.save(commit=False)
                camp.business = bdns
                camp.time_to_next = 2
                camp.rank = 1
                camp.address = addr
                camp.display = 1

            camp.url = 'http://test1.com'
            camp.current_promotion = promo
            camp.enabled = True
            camp.save()
            cp = promo
            camp.promotions.add(cp)

可能是什么问题？