How to make these phone calls stop!

So for the past couple of weeks I have been getting random phone calls from numbers I don’t recognize. They’re generally at exactly 9:00 AM. And as I have an afternoon job I’m usually asleep and they wake me up. I’m usually not able to get to my phone in time to answer, because my sleeping brain is like NO DO NOT GET UP GO AWAY PHONE NONONO! But occasionally, I’ve picked up, and there’s just silence on the other end, and then it disconnects. When I call any of these numbers back, I get an automated message that the number I called is not in service.

I have Verizon, if that helps. And most of the numbers are coming from 917 numbers, which is the New York City area code (which is, incidentally, my area code).

What do I do? I can’t put my phone on silence at night, because I need to keep it on in case it’s an emergency and someone does need to reach me. And it’s a different phone number every time, so I can’t block the calls.