Count number of records by date in Django

Now that Extra() is being depreciated a more appropriate answer would use Trunc such as this accepted answer

Now the OP's question would be answered as follows

from django.db.models.functions import TruncDay

Review.objects.all()
    .annotate(date=TruncDay('datetime_created'))
    .values("date")
    .annotate(created_count=Count('id'))
    .order_by("-date")

This should work (using the same MySQL specific function you used):

Review.objects.filter(venue__pk=2)
    .extra({'date_created' : "date(datetime_created)"})
    .values('date_created')
    .annotate(created_count=Count('id'))