next_birthdays.py

from datetime import date, timedelta
from django.db.models import Q

def next_birthdays(qs, days, fieldname):
    def f(*args):
        args = list(args)
        last = args.pop(-1)
        names = [fieldname] + args
        return {'__'.join(names): last}
    now = date.today()
    limit = now + timedelta(days=days)
    lo_day = now.day
    lo_month = now.month
    hi_day = limit.day
    hi_month = limit.month
    q = Q(f('month', 'gte', lo_month))
    q &= Q(f('day', 'gte', lo_day))
    q &= Q(f('month', 'lt', hi_month))
    q &= Q(f('day', 'lt', hi_day))
    return qs.filter(q)