Why is my date in python wrong after formating using timedelta?

Question

I am using Django and have a problem with a date that I need to calculate. The Variable data > test should be 17:00 and not 15:00. Why does this happen as soon as I format the date?

My timezone is Europe/Berlin. Changing the timezone has to effect to the time printing in test. It is always -2h

def date(req):
    now = timezone.now()
    model = MyModel.objects.filter(date__gt=now).first()
    next = model.date
    future = timezone.timedelta(hours=float(model.future)) #model.future = 1.5
    open = next-future
    date = next.strftime('%Y/%m/%d')
    data = {
        'next': next,
        'date': date,
        'time': open.astimezone(timezone.utc).strftime('%Y-%m-%d %H:%M:%S.%f'),
        'test': open.strftime('%Y/%m/%d %H:%M:%S%z')
    }

What I get:

next: 20. November 2021 18:30
date: 2021/11/20
time: 2021-11-20 15:15:00.000000
test: 2021/11/20 15:00:00+0000

Answer 1

This works for me.

from django.utils import timezone

def date(req):
    now = timezone.now()
    model = MyModel.objects.filter(date__gt=now).first()
    next = model.date
    future = timezone.timedelta(hours=float(model.future)) #model.future = 1.5
    open = next-future
    date = timezone.localtime(open)
    data = {
        'next': date.strftime('%Y/%m/%d %H:%M:%S'),
        'date': date.strftime('%Y/%m/%d'),
        'time': date.strftime('%H:%M:%S'),
    }