_setPublishedAtBlogStrings(momentDate) {
        if (momentDate) {
            let blogTimezone = this.settings.timezone;
            let publishedAtBlog = moment.tz(momentDate, blogTimezone);

            this.set('publishedAtBlogDate', publishedAtBlog.format('YYYY-MM-DD'));
            this.set('publishedAtBlogTime', publishedAtBlog.format('HH:mm'));
        } else {
            this.set('publishedAtBlogDate', '');
            this.set('publishedAtBlogTime', '');
        }
    }
Note:
If you create a post and publish it, we send seconds to the database.
If you edit the post afterwards, ember would send the date without seconds, because
the `publishedAtUTC` is based on `publishedAtBlogTime`, which is only in seconds.
The date time picker doesn't use seconds.

This condition prevents the case:
  - you edit a post, but you don't change the published_at time
  - we keep the original date with seconds

See https://github.com/TryGhost/Ghost/issues/8603#issuecomment-309538395.