import socket, ssl, datetime

def get_ssl_expiration(domain, port=443):
    try:
        ctx = ssl.create_default_context()
        with socket.create_connection((domain, port), timeout=5) as sock:
            with ctx.wrap_socket(sock, server_hostname=domain) as ssock:
                cert = ssock.getpeercert()
                notAfter = cert.get('notAfter')
                if notAfter:
                    # Example certificate expiry format: "Jun  1 12:00:00 2025 GMT"
                    exp_date = datetime.datetime.strptime(notAfter, '%b %d %H:%M:%S %Y %Z')
                    return exp_date.strftime("%m/%d/%Y")
        return "NO SSL"
    except Exception:
        return "NO SSL"