Inconsistent Behavior of SelectDateWidget._parse_date_fmt()

[Peter-Gehlert]

When looking to change the format of the date in the SelectDateWidget from the default of Month, Day, Year to Day, Month, Year; all advice i found pointed to changing the DATE_FORMAT in settings.py however I discovered an error with the implementation in the widget that prevents this from changing the format as expected.

When generating the contextwidgetsubwidgets in the SelectDateWidget.get_context() method, the implementation relies on the SelectDateWidget._parse_date_fmt() static method to determine the date format.

@staticmethod
def _parse_date_fmt():
    fmt = get_format("DATE_FORMAT")

The current implementation of _parse_date_fmt() disregards the lang and use_l10n parameters, leading to inconsistencies in date formatting. Specifically, the use_l10n parameter is always set to True by default within the get_format() function:

if use_l10n is None:
    use_l10n = True
if use_l10n and lang is None:
    lang = get_language()

This results in the function always returning the default date format as specified by the LANGUAGE_CODE setting or the language determined by USE_I18N regardless of any language or localization preferences specified elsewhere.

Expected Behavior:
The _parse_date_fmt() method should take into account the lang and use_l10n parameters to allow for language-specific and localization-aware date formatting. This would ensure that the generated date format respects the desired language and localization settings.

Recommendation:
Modify the _parse_date_fmt() method to properly handle the lang and use_l10n parameters when retrieving the date format. This can be achieved by passing these parameters to the get_format() function within the method.

@staticmethod
def _parse_date_fmt(lang=None, use_l10n=None):
    fmt = get_format(
        "DATE_FORMAT", 
        lang=translation.get_language(), 
        use_l10n=getattr(django.conf.settings, 'USE_L10N')
    )