Filter published BlogPosts in Mezzanine

Currently in Mezzanine I have some blog posts that are set to be published, but with a date that is a few days later.

At the moment these blog posts objects are visible to view by returning these objects by context. How do I filter out these that are not yet published? If I go to the blog post URL it gives me a 404 error, so that's correct though.

The model:

class BlogPost(Displayable, Ownable, RichText, AdminThumbMixin):
    """
    A blog post.
    """

    categories = models.ManyToManyField("BlogCategory",
                                        verbose_name=_("Categories"),
                                        blank=True, related_name="blogposts")
    allow_comments = models.BooleanField(verbose_name=_("Allow comments"),
                                         default=True)
    comments = CommentsField(verbose_name=_("Comments"))
    rating = RatingField(verbose_name=_("Rating"))
    featured_image = FileField(verbose_name=_("Featured Image"),
        upload_to=upload_to("blog.BlogPost.featured_image", "blog"),
        format="Image", max_length=255, null=True, blank=True)
    related_posts = models.ManyToManyField("self",
                                 verbose_name=_("Related posts"), blank=True)

    admin_thumb_field = "featured_image"

    class Meta:
        verbose_name = _("Blog post")
        verbose_name_plural = _("Blog posts")
        ordering = ("-publish_date",)

    def get_absolute_url(self):
        """
        URLs for blog posts can either be just their slug, or prefixed
        with a portion of the post's publish date, controlled by the
        setting ``BLOG_URLS_DATE_FORMAT``, which can contain the value
        ``year``, ``month``, or ``day``. Each of these maps to the name
        of the corresponding urlpattern, and if defined, we loop through
        each of these and build up the kwargs for the correct urlpattern.
        The order which we loop through them is important, since the
        order goes from least granular (just year) to most granular
        (year/month/day).
        """
        url_name = "blog_post_detail"
        kwargs = {"slug": self.slug}
        date_parts = ("year", "month", "day")
        if settings.BLOG_URLS_DATE_FORMAT in date_parts:
            url_name = "blog_post_detail_%s" % settings.BLOG_URLS_DATE_FORMAT
            for date_part in date_parts:
                date_value = str(getattr(self.publish_date, date_part))
                if len(date_value) == 1:
                    date_value = "0%s" % date_value
                kwargs[date_part] = date_value
                if date_part == settings.BLOG_URLS_DATE_FORMAT:
                    break
        return reverse(url_name, kwargs=kwargs)

Is there a way by retrieving ONLY posts that are truly published?

Is there a way by retrieving ONLY posts that are truly published?

This grabs the blog posts published on or before today, using the query publish_date <= today:

import datetime

BlogPost.objects.filter(publish_date__lte=datetime.date.today())