When putting in the "Date Labor or Materials First Delivered", should I use the date that our office very first begins detailing the project (in which we are paying for labor to our detailing employee), at the time the materials are delivered to our fabrication shop and "shop labor" begins the fabrication process, OR NOT until materials and/or labor occurs ON SITE (upon installation)?? Please advise. (While I am entering NM state below, I am really curious how to answer this question nationally, since our projects are spread out all over). Thank you!