How to filter queryset less than 60 months ago?

Question

models.py

class Preschooler(Model):
    first_name = models.CharField(max_length=100)
    last_name = models.CharField(max_length=100)
    birthday = models.DateField(null=True, blank=True)

    def age_months(self):
        today = date.today()
        date_diff = today - self.birthday
        in_days = date_diff.days

        return int((in_days) / (365 / 12))

I want to filter preschooler that are less than 60 months using their birthday like this:

Preschooler.objects.filter(birthday__month__lst=60)

How can I achieve this?

Answer 1

You can use Python relativedelta with datetime.today() ^[Python-doc] so:

from datetime import datetime

from dateutil.relativedelta import relativedelta 
less_than_60_mon = datetime.today() - relativedelta(months=60)
   
Preschooler.objects.filter(birthday__lt=less_than_60_mon)