Watch the 40-second video below to see exactly how to schedule blog posts in WordPress:
When creating a blog post directly in WordPress, go to the Publish box found in the pane at the right. Look for the section labeled “Publish Immediately” and click the Edit link. Choose the desired date and time, click OK, and click the Publish button.
How to Schedule Blog Posts in WordPress Using Third Party Tools

Scheduling blog posts with Windows Live Writer
You can also schedule blog posts in WordPress using third party blogging tools such as Windows Live Writer, a free tool that's part of Microsoft's Windows Live Essentials. To schedule a blog post in Windows Live Essentials, you'll first need to go into your WordPress dashboard and click on Settings > Writing Settings >Remote Publishing and place a check mark next to “Enable the WordPress, Movable Type, Metaweblog, and Blogger XML-RPC publishing protocols.”
From there, open Windows Live Writer and enter your sign-on credentials for your blog. Now, create a blog post. When you're ready to schedule it, go to the upper right corner of the screen where you'll see a dropdown menu field with the words “Set post date.” Click the dropdown arrow and choose your date.Finally, click the Publish button. Your blog post will upload in draft mode and will be automatically published at the prescribed time and date.
How to Schedule Blog Posts with iPad Apps

Scheduling blog posts with Blogsy
Numerous blogging apps are available for iPads, many of which allow you to schedule WordPress blog posts. Again, you'll need the XML-RPC publishing protocol enabled in WordPress. Let's use the Blogsy app as an example.
Open Blogsy on your iPad and create a blog post as you normally would. When you're ready to publish, tap the gear icon to the left of your post's title. Choose your blog from the list and tap on Publish Date. Use the spinner to select the time and date you'd like to the blog post to be published. Tap Publish.
Blogsy will upload your blog post to WordPress where it will wait patiently in draft mode until the scheduled time and date arrive.
These are but a few of the many tools you can use to schedule blog posts in WordPress. How will you put them to good use?