Queryset of people with a birthday in the next X days

Question

how do i get queryset of people with a birthday in the next X days? I saw this answer, but it does not suit me, because gets people only with current year of birth.

Answer 1

Assuming a model like this--

class Person(models.Model):
    name = models.CharField(max_length=40)
    birthday = models.DateTimeField() # their next birthday

The next step would be to create a query filtering out any records with birthdays having a month and day in between (now.month, now.day) and (then.month, then.day). You can actually access the month and day attributes of the datetime object using the queryset API by passing Person.objects.filter a keyword argument like this: "birthday__month." I tried this with an actual queryset API method like "birthday__month__gte" and it failed though. So I would suggest simply generating a literal list of month/day tuples representing each (month, day) in the date range you want records for, then compose them all into a query with django.db.models.Q, like so:

from datetime import datetime, timedelta
import operator

from django.db.models import Q

def birthdays_within(days):

    now = datetime.now()
    then = now + timedelta(days)

    # Build the list of month/day tuples.
    monthdays = [(now.month, now.day)]
    while now <= then:
        monthdays.append((now.month, now.day))
        now += timedelta(days=1)

    # Tranform each into queryset keyword args.
    monthdays = (dict(zip(("birthday__month", "birthday__day"), t)) 
                 for t in monthdays)


    # Compose the djano.db.models.Q objects together for a single query.
    query = reduce(operator.or_, (Q(**d) for d in monthdays))

    # Run the query.
    return Person.objects.filter(query)

After debugging, this should return a queryset with each person who has a birthday with month and day equal to any of the months or days in the specified list of tuples.