e is returned as the number of milliseconds since January 1, 1970 GMT. The header name is case insensitive.

 <p>
 If the request did not have a header of the specified name, this method returns -1. If there are multiple headers
 with the same name, this method returns the value of the first header in the request. If the header can't be
 converted to a date, the method throws an <code>IllegalArgumentException</code>.</div>
<dl class="notes">
<dt>Parameters:</dt>
<dd><code>name</code> - a <code>String</code>