blag / django-tz-detect

Easy user timezone detection for Django

django-tz-detect

This app will auto-detect a user's timezone using JavaScript, then configure Django's timezone localization system accordingly. As a result, dates shown to users will be in their local timezones.

Authored by Adam Charnock, and some great contributors.

How it works

On the first page view you should find that tz_detect places a piece of asynchronous JavaScript code into your page using the template tag you inserted. The script will obtain the user's GMT offset using getTimezoneOffset, and post it back to Django. The offset is stored in the user's session and Django's timezone awareness is configured in the middleware.

The JavaScript will not be displayed in future requests.

Installation

1. Either checkout tz_detect from GitHub, or install using pip:

   pip install django-tz-detect

2. Add tz_detect to your INSTALLED_APPS:

   INSTALLED_APPS += (
       'tz_detect',
   )

3. Be sure you have the django.template.context_processors.request processor

   TEMPLATES = [
       {
           ...
           'OPTIONS': {
               'context_processors': [
                   ...
                   'django.template.context_processors.request',
               ],
           },
       },
   ]

4. Update your urls.py file:

   urlpatterns += [
       url(r'^tz_detect/', include('tz_detect.urls')),
   ]

5. Add the detection template tag to your site, ideally in your base layout just before the </body> tag:

   {% load tz_detect %}
   {% tz_detect %}

6. Add TimezoneMiddleware to MIDDLEWARE:

   import django
   
   MIDDLEWARE += (
       'tz_detect.middleware.TimezoneMiddleware',
   )
   
   if django.VERSION < (1, 10):
       MIDDLEWARE_CLASSES += (
           'tz_detect.middleware.TimezoneMiddleware',
       )

7. (Optional) Configure the countries in which your app will be most commonly used:

   # These countries will be prioritized in the search
   # for a matching timezone. Consider putting your
   # app's most popular countries first.
   # Defaults to the top Internet using countries.
   TZ_DETECT_COUNTRIES = ('CN', 'US', 'IN', 'JP', 'BR', 'RU', 'DE', 'FR', 'GB')

Please see example application. This application is used to manually test the functionalities of this package. This also serves as a good example.

You need only Django 1.8 or above to run that. It might run on older versions but that is not tested.

Caveats

• Django's timezone awareness will not be available on the first page view
• This method requires JavaScript
• Timezone detection is done entirely from the user's GMT offset, not from their location

Future expansion

• A hook to allow the timezone to be stored against a user
• Allow timezones to be manually specified
• Improve timezone detection
• Optionally using HTML5's location API for better timezone determination