老师，我在前端提交日期格式的时候，出错，返回信息个人资料修改失败。如果在form表单中把属性是日期的birthday字段去掉，就不会出问题，请问这是怎么回事呢

class UserView(View):

    def get(self, request):
        user = request.user
        return render(request, 'employee.html', {'user': user})

    def post(self, request):
        user = request.user
        user_profile = get_object_or_404(Employee, user=user)
        user_form = UploadImageForm(request.POST)
        if user_form.is_valid():
            user_profile.name = user_form.cleaned_data['name']
            user_profile.birthday = user_form.cleaned_data['birthday']
            user_profile.moblie = user_form.cleaned_data['moblie']
            user_profile.email = user_form.cleaned_data['email']
            user_profile.save()
            return HttpResponseRedirect(reverse('users:employee'))
        else:
            return HttpResponse('{"status":"fail", "msg":"个人资料修改失败"}', content_type='application/json')