In WordPress you can set the date for something into the future—think of it as a dorky sort of time travel—so that you can write (if you wanted to) weeks worth of posts in an afternoon. WordPress will “update” your blog by posting your content at the time you specify each day.
Here’s how to do it.
In the bottom right of your posting page you will see a section called Post Timestamp. (Only when posting posts will you see this.) As it stands it should display the date and time that you opened up your posting page. If you change the date/check Edit Timestamp you can set the date for the appearance of the post to a later time.
Select the date and time you would like the post to display at (the above reads May 25, 2007 at 2:09pm). Time is displayed in military time, so take that into consideration.
After the date is set (and your post is finished, of course) hit Publish. This will be scary the first time, as you don’t want the post to show up right away. But rest assured (after checking your site, which you will do) that your post isn’t there yet.
Oh, and anything posted with a future timestamp can still be edited under Manage Posts. Keep in mind changing something and hitting Save will not affect your timestamp, so there are no worries about messing up your timestamp settings when dropping in to change a typo.