fix wrong django timezone

django_fix_timezone.py

import sys
import os.path
from datetime import datetime, timedelta
from pprint import pprint
import pytz

__dir__ = os.path.dirname(__file__)
__proj_dir__ = os.path.dirname(__dir__)
sys.path.insert(0, __proj_dir__)

import django
from django.conf import settings
from django.db import transaction, models
import django.apps


django.setup()


original_tz = 'America/Chicago'
current_tz = 'Asia/Shanghai'


def get_model_datetime_fields(model):
    fields_need_fix = []
    for f in model._meta.get_fields():
        if isinstance(f, models.DateTimeField):
            fields_need_fix.append(f.attname)
    return fields_need_fix


def fix_datetime(val):
    TZ = pytz.timezone(original_tz)
    val = val.astimezone(pytz.UTC)
    val = val.astimezone(TZ)
    val = val.replace(tzinfo=None)
    return val


@transaction.atomic
def fix_model(model, fields):
    for obj in model.objects.all():
        for field in fields:
            val = getattr(obj, field)
            if val:
                fixed_val = fix_datetime(val)
                print(val, fixed_val)
                setattr(obj, field, fixed_val)
        obj.save()


if __name__ == "__main__":
    for model in django.apps.apps.get_models()[::-1]:
        if not model.objects.count():
            continue
        fields = get_model_datetime_fields(model)
        if not fields:
            continue
        print(model)
        print('  ', fields)

        fix_model(model, fields)