问题是我需要 settings.py 文件中的 ISO 和 UK 日期格式，如下所示:

The problem turned out to be that I needed both the ISO and UK date formats in the settings.py file like so:

DATE_INPUT_FORMATS = ('%d-%m-%Y','%Y-%m-%d')

然后将 forms.py 调整为以下内容:

and then the forms.py adjusted to the following:

class ClientDetailsForm(ModelForm):
    date_of_birth = DateField(input_formats=settings.DATE_INPUT_FORMATS)
    class Meta:
        model = ClientDetails

为什么 USE_L10N = True 不能这样做，我不知道！

Why USE_L10N = True can't just do this I don't know!

[感谢这个和这个]