The blog is the public news and updates section of the site. If you have administrator access, you can write posts and choose when each one goes live. Everyone else sees only the finished posts on the public blog.
Every post is in one of three states, shown as a colored badge next to its title in the admin post list:
A saved draft stays private until you publish or schedule it.
The post now shows the Scheduled badge and stays hidden from the public blog until the time you chose. At that time the post goes live automatically, usually within about a minute. Once it is live, its badge changes to Published.
You do not need to do anything else at the scheduled time. The post publishes on its own.
You have a few ways to publish immediately:
Turn off the Published toggle and save, or click Unpublish on a live post. The post comes off the public blog and returns to Draft. Unpublishing also cancels any schedule, so a post you take down will not come back on its own. To put it back, publish it again or set a new publish time.