如何在特定的Django管理模型中更改时区？

TIME_ZONE = 'Asia/Shanghai'

from django.db import models
from django.utils import timezone
import pytz

class MyModel(models.Model):
    name = models.CharField(max_length=100)
    created_at = models.DateTimeField()

    def save(self, *args, **kwargs):
        tz = pytz.timezone('Asia/Shanghai')  # 设置目标时区
        self.created_at = timezone.now().astimezone(tz)
        super().save(*args, **kwargs)

from django.contrib import admin

class MyModelAdmin(admin.ModelAdmin):
    list_display = ('name', 'get_created_at')

    def get_created_at(self, obj):
        tz = pytz.timezone('Asia/Shanghai')  # 设置目标时区
        return obj.created_at.astimezone(tz)

admin.site.register(MyModel, MyModelAdmin)