Django: Use of DATE_FORMAT, DATETIME_FORMAT, TIME_FORMAT in settings.py?

Question

I would like to globally (through my entire site, admin and front-end) adjust the way dates and time are displayed to my likings, but I cannot figure out what is going on with the DATE_FORMAT, DATETIME_FORMAT and TIME_FORMAT variables in settings.py.

In this question it says that the settings are ignored. The question is over a year old though. In the Django documentation it says they can be used when you have USE_L10N = True and apparently something changed in Django 1.2. According to this however there might be a bug.

I am currently using Django 1.2 and when I have USE_L10N = True it just ignores the date(time) format in settings.py. When I have USE_L10N = False it also seems to ignore them.

Is there a way to globally customize the date and time display? Or should I create my own custom formats file as Karen suggests in the Django Users Google Group post?

Answer 1

Searching through the source shows that DATETIME_FORMAT, etc., are only used when django.utils.formats.localize() is called, and that only seems to be called when django.template.VariableNodes are rendered.

I'm not sure when exactly VariableNodes are used in template rendering, but I would guess that if you have settings.USE_L10N turned on and you have a VariableNode, it will be localized.

localize looks like this:

def localize(value):
    """
    Checks if value is a localizable type (date, number...) and returns it
    formatted as a string using current locale format
    """
    if settings.USE_L10N:
        if isinstance(value, (decimal.Decimal, float, int)):
            return number_format(value)
        elif isinstance(value, datetime.datetime):
            return date_format(value, 'DATETIME_FORMAT')
        elif isinstance(value, datetime.date):
            return date_format(value)
        elif isinstance(value, datetime.time):
            return time_format(value, 'TIME_FORMAT')
    return value

To answer your question, I'd probably write a quick context processor that called localize() on everything in the context.