When creating a blog post with a backdated 'Posting Date' the post is incorrectly set as today

Summary

If you create a blog post in Confluence and set a backdated or old date as the Posting Date then hit publish the blog is still posted under today's date according to the blog location.

Steps to Reproduce

1. Create a new blog post
2. Enter an 2015-01-01 as the Posting Date in the bottom left corner
3. Hit publish

Expected Results

The blog should appear under the location 2015 / January / 01

Actual Results

The blog is actually posted under today's date (in my case 2016 / January / 02)

Workaround

No known workaround.