title: puting a time limit on something with flutter
body: <p>I have an flutter app with many &quot;tasks&quot;. Users can earn XP and level up by completing tasks.
  I want some tasks only to be able to be do once a day or once a week. I can create a &quot;Duration&quot; when task is complete but after that I am lost.</p>
  <p>for example I have a variable like this.</p>
  <pre><code>Duration oneDay = Duration(hours: 24);
  </code></pre>
  <p>How can I disable -so the user can see but can't click- a completed task for one day?</p>