By default, posts that are sent from MarsEdit to your blog are published immediately. Many blog hosting services support a feature that facilitates “scheduled posts”, which are not published immediately when sent to your blog. To take advantage of this, use the Post -> Set Date to set a date in the future when you’d like the post to go live:

When you send the post to your blog, instead of being published immediately it will enter a “scheduled” state. This behavior is reliable on most popular blogging services, including WordPress and Tumblr. However, the first time you use this feature, we recommend testing it on a post that is not critically important to keep private, in case there are any nuances to the way your blog handles future-dated posts. You can verify the “scheduled” status of a post by examining the post status in the web-based admin interface to your blog.