class SpringSemesterEventManager(models.Manager):

    def get_query_set(self):
        return super(SpringSemesterEventManager, self).get_query_set().filter(
            is_spring_semester=True)


class FallSemesterEventManager(models.Manager):

    def get_query_set(self):
        return super(FallSemesterEventManager, self).get_query_set().filter(
            is_fall_semester=True)


class Event(models.Model):
    event_date = models.DateField()

@property
def is_spring_semester(self):
    month = self.event_date.month
return True if month >= 1 and month <= 5 else False

@property
def is_fall_semester(self):
    month = self.event_date.month
return True if month >= 8 and month <= 12 else False
objects = models.Manager()
spring_semester = SpringSemesterEventManager()
fall_semester = FallSemesterEventManager()
Как определить диапазон месяцев для любого года в модели Django?