The easiest way to see if it is an NHL charter is to look at the activity log of past flights (scroll down here):
https://flightaware.com/live/flight/...910Z/KPHL/KDEN
If you know where the other team is coming from you can use flightaware.com to monitor the incoming flight live to see how late they get in. (Umm, not that I have ever been geeky enough to do that).
