Django - Display 2 Datefields for a Course. When it starts and when it ends

Question

class Kurs(models.Model):
    # Kursleiter =
    # Thema
    name = models.CharField(max_length=200)
    beschreibung = models.TextField(null=True, blank=True)
    # teilnehmer =
    # auto_now macht immer, wenn wir was ändern einen Timestamp
    updated = models.DateTimeField(auto_now=True)
    # auto_now_add macht nur einen Timestamp
    created = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return self.name

This is my Models.py Class. I want to create 2, in the Admin Panel visible Fields where I can enter the Start Date and End Date for my Courses.

When I tried it this way:

start_date = models.DateField(default=timezone.now)
end_date = models.DateField(default=timezone.now)
start_time = models.TimeField()
end_time = models.TimeField()

My Commandline Displays this Error:

It is impossible to add a non-nullable field 'end_date' to kurs without specifying a default. This is because the database needs something to populate existing rows.

I hoped to get 2 Date Fields in my Admin Panel in the View, showed in the ImageAdmin Panel, where I wish to display

Answer 1

Here all date and time fields show me on admin panel, excluding (created ,updated) fields follow bellow code.

models.py

class Kurs(models.Model):
    name = models.CharField(max_length=200)
    beschreibung = models.TextField(null=True, blank=True)
    updated = models.DateTimeField(auto_now=True)
    created = models.DateTimeField(auto_now_add=True)

    start_date = models.DateField(default=timezone.now)
    end_date = models.DateField(default=timezone.now)
    start_time = models.TimeField()
    end_time = models.TimeField()

    def __str__(self):
        return self.name

admin.py

@admin.register(Kurs)
class KursAdmin(admin.ModelAdmin):
    list_display = ("end_time", "start_time", "end_date", "start_date", "created", "updated", "beschreibung", "name","id")[::-1]

output in admin panel