Surgical DOS when julian dates overlap

I have an appendectomy surgical case that started at 11:30 pm on 4/10/10 and ended at 00:30 AM the next day, 4/11/10.

What is the appropriate DOS that should be billed as well as documented on the operative note?

I was verbally told back in 2007 at a workshop that the DOS is when the surgical procedure is completed. I can not find any supporting documentation to support this. To me, this makes sense, though. Just like a 24-hour monitoring test, it is when it is completed.

Can you help and provide some kind of link or documentation to support this? I have addressed this question to our Compliance, HIM dept and CMS "ask a question" and no one has a document to support my thought.

I GREATLY APPRECIATE ANY FEEDBACK ON THIS.
THANK YOU!!!!!!!!!

link

I do not have a link but my understanding is the DOS is when you make the incision. The DOS must match the hospital DOS for the procedure. The claim form has from and to dates.