Django为asteriks*建立了哪些领域的模型?

我正在Django建立一个数据库。 在models.py中,asteriks*的正确字段类型是什么? 我试过textfield,integerfield和charfield。

class Task(models.Model):
    class Meta:
        verbose_name_plural = 'Task'

    save_date = models.DateTimeField(default=timezone.now())
    hour_cr = models.TextField(default='*', validators=[MaxValueValidator(24), MinValueValidator(0)])
    minute_cr = models.TextField(default='*', validators=[MaxValueValidator(59), MinValueValidator(0)])
    day_of_the_month_cr = models.TextField(default='*', validators=[MaxValueValidator(31), MinValueValidator(0)])
    month_cr = models.TextField(default='*', validators=[MaxValueValidator(12), MinValueValidator(1)])
    day_of_week_cr = models.TextField(default='*', validators=[MaxValueValidator(7), MinValueValidator(1)])
    name_task = models.TextField(max_length=25)
    user = models.ForeignKey(User, on_delete=models.CASCADE)

attributeError:模块'django.db.models'没有属性'characterdata'