SO jQuery Fiddle

Test Fiddle mainly for SO Questions jQuery 1.4.3, UI 1.8.5

by Nick Craver

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.5/themes/ui-lightness/jquery-ui.css">
Always? <input type="checkbox" class="always" />
<div id="dates">
    A div with dates
</div>

JavaScript

$(function () {
  $('.always').change(function () {                
     $('#dates').toggle(!this.checked);
  }).change(); //ensure visible state matches initially
});