<link href="css/main.css?1422439996" rel="stylesheet">
You have the file main.CSS in your web page and have been cached before when the user visited your web page so when you update the file content the browser will check only on the file name and it not be changed so will use the old cached file.
But when you add the release date as suffix when the user visit your page after the release date the browser will detect new file name so will load it and then cache it till the next release.
The next this is to go and talk with your team on how can you deploy this, if you needed farther details you can contact me directly or in the comments section. Don’t forget the most important thing subscribe to my news letter to get the upcoming posts directly in your mailbox and share this article to help others.