djangoの投稿フォームにてバリデーションエラーが発生

前提・実現したいこと

djangoにてmodelformにてデータ書き込みフォームを作成しています。
データ入力、投稿を実行すると、以下のようなdatetimeの形式違いによるバリデーションエラーが発生してしまっています。
今回は、datetimefieldの書き込みは行わないため、どうしてエラーが発生しているのかがわからない状況です。

発生している問題・エラーメッセージ

Internal Server Error: /minervini-detail/2379
Traceback (most recent call last):
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/core/handlers/base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "//django/jangotest_2/app_1/test_app/views.py", line 839, in MineStockDetail
    stock_data.save()
  File "//jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/base.py", line 726, in save
    self.save_base(using=using, force_insert=force_insert,
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/base.py", line 763, in save_base
    updated = self._save_table(
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/base.py", line 845, in _save_table
    updated = self._do_update(base_qs, using, pk_val, values, update_fields,
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/base.py", line 899, in _do_update
    return filtered._update(values) > 0
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/query.py", line 802, in _update
    return query.get_compiler(self.db).execute_sql(CURSOR)
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/sql/compiler.py", line 1535, in execute_sql
    cursor = super().execute_sql(result_type)
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/sql/compiler.py", line 1156, in execute_sql
    sql, params = self.as_sql()
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/sql/compiler.py", line 1501, in as_sql
    val = field.get_db_prep_save(val, connection=self.connection)
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/fields/__init__.py", line 842, in get_db_prep_save
    return self.get_db_prep_value(value, connection=connection, prepared=False)
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/fields/__init__.py", line 1427, in get_db_prep_value
    value = self.get_prep_value(value)
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/fields/__init__.py", line 1406, in get_prep_value
    value = super().get_prep_value(value)
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/fields/__init__.py", line 1266, in get_prep_value
    return self.to_python(value)
  File "//django/jangotest_1/jangotest_1/lib/python3.8/site-packages/django/db/models/fields/__init__.py", line 1388, in to_python
    raise exceptions.ValidationError(
django.core.exceptions.ValidationError: ['“” は無効な形式の値です。 YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] 形式でなければなりません。']
[24/Oct/2021 10:45:56] "POST /minervini-detail/2379 HTTP/1.1" 500 136019

該当のソースコード

model
1class real_minervini(models.Model):
2      id = models.IntegerField(primary_key=True)
3      name = models.CharField(max_length=255)
4      code = models.IntegerField()
5      buy_day = models.DateTimeField(null=True,blank=True)
6      announce = models.DateTimeField(null=True,blank=True)
7      chart = models.CharField(max_length=255,null=True,blank=True)
8      pattern = models.CharField(max_length=255)
9      zikasougaku = models.CharField(max_length=255)
10      market = models.CharField(max_length=255)
11      aim = models.IntegerField(null=True,blank=True)
12      buy_cost = models.FloatField()
13      high_cost = models.FloatField()
14      now_cost = models.FloatField()
15      future = models.CharField(max_length=255,null=True,blank=True)
16      checkbox_buy = models.BooleanField(verbose_name='売り', default=False)
17      image1 = models.ImageField(upload_to='images',verbose_name='イメージ画像',null=True,blank=True)
18      image2 = models.ImageField(upload_to='images',verbose_name='イメージ画像',null=True,blank=True)
19      image3 = models.ImageField(upload_to='images',verbose_name='イメージ画像',null=True,blank=True)
20      industry1 = models.CharField(max_length=255,null=True,blank=True)
21      industry = models.CharField(max_length=255)
22      other1 = models.CharField(max_length=255)
23      other2 = models.CharField(max_length=255)
24      other3 = models.CharField(max_length=255)
25      other4 = models.CharField(max_length=255)
26      other5 = models.CharField(max_length=255)
27      benefit = models.FloatField()
28      benefit_rate = models.FloatField()

form
1from django.forms.models import ModelForm
2from test_app.models import real_minervini
3
4class formmine(ModelForm):
5  class Meta():
6    model = real_minervini
7    fields = ['aim','chart','future','checkbox_buy','image1','image2','image3','industry1']
8    labels = {
9      'aim':'狙いの値段',
10      'chart':'チャート形状',
11      'future':'国策や成長産業か',
12      'checkbox_buy':'買い',
13      'image1':'図1',
14      'image2':'図2',
15      'image3':'図3',
16      'industry1':'業種'
17    }

views
1def MineStockDetail(request,code):
2    stock_data = get_object_or_404(real_minervini,code=code)
3    form = formmine(request.POST or None)
4    if request.method == 'POST':
5        print("good")
6        if form.is_valid():
7            stock_data.aim = form.cleaned_data["aim"]
8            stock_data.save()
9            return redirect('test_app:buy_minervini')
10        else:
11            return redirect('test_app:buy_minervini')
12    return render(request,'test_app/minervini_detail.html',{
13            'data':stock_data,
14            'form':form
15        })

minervini_detail.html
1#minervini_detail.html
2{% extends "test_app/base.html" %}
3{% block main %}
4{% load mathfilters %}
5<h2 class="comment-top">詳細編集画面</h2>
6
7<form method="POST" action="" enctype="multipart/form-data">
8  {{ form.as_p }}
9  {% csrf_token %}
10  <input type="submit" value="投稿する" class="btn btn-danger">
11</form>
12
13{% endblock %}