Need ability (OM Extension) to apply credit check hold if last update date is more that 30 days past

Summary:

We have created the extension to skip credit check on order revision if order total amount not more than original order amount, however we also want to apply credit check, if last update date is more than 30 days past. below is the code which we have used

Content (please ensure you mask any confidential information):

import oracle.apps.scm.doo.common.extensions.ValidationException;
import oracle.apps.scm.doo.common.extensions.Message;

String headerId = header.getAttribute("HeaderId");
String refHeaderId = header.getAttribute("ReferenceHeaderId");

String OrderNumber = header.getAttribute("OrderNumber");

//skip if its new order
if( refHeaderId == null ) return;

def currTotal;
def refTotal;