django and timezone per user displayed in templates

Question

Here is what I am trying to do:

1. I want datetimes to be stored in UTC in the database.
2. I want them to be displayed in the US/Eastern timezone for the admin.
3. Each user has a field for the timezone so I'd like to display the times for their timezone when they are connected.

I started with that in the settings.py file:

LANGUAGE_CODE = 'en-us'
TIME_ZONE = 'US/Eastern'
USE_I18N = True
USE_L10N = True
USE_TZ = True

It looks like #1 and #2 are ok.

For #3, I tried using something like that in the templates to display the times with the user timezone but it does not seem to work.

{% load tz %}
{% timezone "Europe/Paris" %}
    Paris time: {{ value }}
{% endtimezone %}