How to use posgresql 'interval' in Django?
You can try this to get the data within the past 12 months.
today= datetime.now()current_month_first_day = today.replace(day = 1)previous_month_last_day = current_month_first_day - timedelta(days = 1)past_12_month_first_day = previous_month_last_day - timedelta(days = 360)past_12_month_first_day = past_12_month_first_day.replace(day = 1) past_12_month_avg = Devc.objects.filter(date__range=(past_12_month_first_day,current_month_first_day)).aggregate(Sum('amount'))['amount']