text: from djongo import models
  
  # Create your models here.
  class Event(models.Model):
      title = models.CharField(max_length=200)
      # description = models.TextField()
      start_time = models.DateField()
      year = models.CharField(max_length=5, blank=True)
      month = models.CharField(max_length=5, blank=True)
      day = models.CharField(max_length=5, blank=True)
  
      def __str__(self):
          return f"ID={self.id} Title={self.title}"
  
      def save(self, *args, **kwargs):
          # print("time=",self.start_time.strftime('%Y'),"year=",self.year)
          if not self.year:
              self.year = self.start_time.strftime('%Y')
          if not self.month:
              self.month = self.start_time.strftime('%m')
          if not self.day:
              self.day = self.start_time.strftime('%d')
          super(Event, self).save(*args, **kwargs)
  