Previewing a draft, then scheduling it

Earlier I created a complex post for my community, which included a table. Since there was no preview button, I saved the post as a draft. Later, when I was done with the post, I tried to schedule it for later, but found that the option to schedule the post is not under the post options during editing.

A preview function would be helpful for these situations, and the ability to schedule a draft would also be appreciated.