Sum of F() expression and timedelta created from F() expression

Question

My Proposal model is defined as follows:

class Proposal(models.Model):
    scheduled_time = models.DateTimeField()
    duration = models.IntegerField() # sto         


        

Answer 1

F() can't be used that way, as @Daniil already pointed out.

A possible solution is to add a new field

end_time = models.DateTimeField()

and override the save method

def save(self, *args, **kwargs):
    if not self.end_time:
        self.end_time = self.scheduled_time + datetime.timedelta(self.duration)
    super(Proposal, self).save(*args, **kwargs)