Post dating blog posts is a very nice option that you can use if you will be away from your computer for a period of time and won't be able to post. It's also nice if you want to announce something, like a sale or new item in your store, at midnight on a specific date.
The best reason for many bloggers to post date is to have an 'artificial' start page to your blog. When you landed on Kubrick's Pick you were greeting by a post containing an image with stars. This post is about our blog reviews about blogs that we like. Well, guess what, that post will be posted in 2010. Nice.....eliminates another reason to go for a real website.
Scheduled post publishing, If you set a post’s date into the future, Blogger will wait to publish until that time comes.
According to Blogger;
Scheduling a post is easy to do: on the post editor page, click the “Post Options” toggle to show the “Post date and time” fields. Then, type a post date and time that’s in the future. When you click the “Publish” button, your post will become “scheduled.” When the date and time of the post arrive, it will be automatically published to your blog.
“Scheduled” posts appear in your Edit Posts list alongside your drafts and published posts. To un-schedule a post, simply save it as a draft any time before it gets published.
If you want to give a post a date in the future but have it appear on your blog now, you’ll need to add in an extra step. First, publish your post with the current date and time. This will make it appear on your blog. Then, edit the post to change the date into the future and publish it again.