title: Live countdown clock with django and sql?
body: <p>If I make a live countdown clock like ebay, how do I do this with django and sql?  I'm assuming running a function in django or in sql over and over every second to check the time would be horribly inefficient.  </p>
  
  <p>Is this even a plausible strategy?</p>
  
  <p>Or is this the way they do it:
  When a page loads, it takes the end datetime from the server and runs a javascript countdown clock against it on the user machine?
  If so, how do you do the countdown clock with javascript? And how would I be able to delete/move data once the time limit is over without a user page load? Or is it absolutely necessary for the user to load the page to check the time limit to create an efficient countdown clock?</p>