title: How to disable previous days in calendar in flutter?
body: <p>I have a datepicker in flutter. Now I need to disable all the previous days from present date in calendar in flutter. When I tried to do , it only disable the one previous day.
  If someone can try this, it will be helpful.</p>
  
  <pre><code>final DateTime picked = await showDatePicker(
      selectableDayPredicate: (DateTime val) =&gt;
      val.day == DateTime.now().day - 1 ? false : true,
      context: context,
      initialDate: DateTime.now(),
      firstDate: new DateTime.now().subtract(new Duration(days: 30)),
      lastDate: DateTime(2101));
  </code></pre>