One way you can make sure that one particular post always comes up first by re-publishing it every time you post something else - and changing the date to a value more recent than the most-recent post.
This can be tiresome, because you need to remember to edit two posts every time that you post. But:
- Its easier than manipulating the date of every single post, and
- You can still use the date-features that Blogger has, so it's unlikely to stop working if Blogger something in the future.
Follow these steps every time you publish to your blog:
1 Do the new (or changed) post, and publish it.
2 Edit the post that you want to go first.
- Go into the Post editor
- Change the content in a small way (eg put in a space, and take it out again).
- Change Post date and time to Automatic.
- Publish it.
If you want to change several posts on the same day, you could do all of them, and only do step 2) after the last one. This will mean that a different post (the most-recently-published one) will come up first for a short time - but this will probably be ok unless you have a very large number of visitors to your blog just after posting.
The option listed above was the only way of doing this for a long time.
But during 2012, Blogger introduced custom re-directs (as a way to let us delete posts, while not losing the traffic that was provided by existing lists to those posts. And so this gives another alternative: you can set up a custom re-direct on your blog's main URL, so that visitors to it always get taken to pretty much anywhere they want. See the first option in giving your blog a home page for more details about how to do this.
Making a "Home Page" for your Blogger blog.
Displaying a gadget only on the home page
Showing your oldest post first in Blogger
Changing the date for a post.
Stopping certain pages from ever appearing on the home page