We are a subcontractor on a large industrial project. The last day we were on site was at the end of May 2021, however, we did not receive a final change order until 08/10/21. We billed the job 100% including retainage when we received the change. I added the end date on the project as 05/30/21 when we received the change order and the notice of lien is due 08/30/21. There are no outstanding unpaid invoices on this job except for the 100% bill and retainage sent last week. Are we able to use the date we received the change order as the end date on the project? Should we file a lien notice on the due date of 8/30 given the only invoices unpaid are 3 weeks old?