title: "Serve static assets with an efficient cache policy" - How many days is best practice?
body: <p>On google page speed test, it logically suggests to setup browser caching for static content, like .js .css etc. </p>
  
  <p><em>"A long cache lifetime can speed up repeat visits to your page."</em></p>
  
  <p>I am setting this up, but for how long?  There must be best practice on this, as I don't know if 7 days or 77 days is a good idea.  Perhaps subjective, site dependent and all that usual stuff, so is the longer the better?  A year perhaps?</p>
  
  <p>I have cache busting enabled, so future updates aren't an issue for my website. </p>