By default Community Server sets the date of a blog post to the time you actually click the new blog post link. Even if it takes you some time to write your post; 10 minutes, 30 minutes, an hour; the blog will show you creating the post at the time you actually clicked the link and not when you actually finished writing it. To change this behavior such that the time for a new post is recorded to be when you saved the post add the following entry to your <CSModules> section in your communityserver.config file.

<add name="TimothyHumphreyBlog" type="TimothyHumphrey.CommunityServer.Blog, TimothyHumphrey.CommunityServer" />