[Answered ]-How to change the display format of datetime fields in the Django admin interface?

I found the answer, thanks to Iain Shelvington.

In admin.py I changed the model registration from

admin.site.register(My_model)

to

@admin.register(My_model)
class My_model_Admin(admin.ModelAdmin):
    list_display = ('created')

Now the datetime format is represented in the table inside the admin interface properly:

It is displayed as 16:00:56 now, because I use CET in settings.py.