I'm not sure what you are asking for "concrete verification" of but here's a link to a police dash cam video that is time stamped. That should give you an idea when Jeremy called 911.
http://www.kctv5.com/story/16612025/dashcam-baby-lisa
Thank you.
I don't question when Jeremy called 911.
I was wondering if there is any evidence that he was working all night?
Perhaps cameras, someone with him, etc.