WordPress Post Date Conditional Script

Before I begin, let me say that I have already scoured this forum looking for an existing fix for my issue…

Here’s my dilemma. I’m migrating to the newer version of Flowplayer that uses ‘HTML5’, but I also need the older Flowplayer script to run on older/archived posts created before (August 29th 2015). The problem is that I cannot have both new and old scripts running on the same page because they share the same ‘namespace’ and will create a conflict.

This is an example of the old script that I need to run in the header for the archived posts:
<script src="http://www.mydomain.com/blog/flwplayerfiles/flowplayer-3.2.13.min.js"></script>

Does anyone know of…or have a PHP or WordPress script that will display this older Flowplayer .js code in the header if the post was written before the aforementioned date?

My WordPress URL/permalink formatting is as follows:
http://www.mydomain.com/blog/2015/08/30/this-is-an-archived-post/

I’m sure this is a simple script for someone who knows what they’re doing. Your help would be greatly appreciated!