set maxDate to specific date

set maxDate to specific date

Hi,

I would like to ask how can I set the datepicker maxDate to a specific date. Itried the following:

  1. if (GetQueryStringValue('id') != "" || GetQueryStringValue('id') != null)
  2. { maxClosing = new Date(<?php echo date("Y", $max_closing_date); ?>, <?php echo date("m", $max_closing_date); ?>, <?php echo date("d", $max_closing_date); ?>); }
  3. else maxClosing = "+90D";

but although my #max_closing_date is 2014-04-19, I am getting  the maxClosing when id is set as: 1970-01-01 like this:

  1. if (GetQueryStringValue('id') != "" || GetQueryStringValue('id') != null)
  2. { maxClosing = new Date(1970, 01, 01); }
  3. else maxClosing = "+90D";