208.184.49.9 has absolutely nothing running, no server, nothing.
132.163.4.101 also has nothing running on it. Although, this is a NIST time server IP address.
192.53.103.104 also has nothing running on it. Though Shodan has logged the NTP (Network Time Protocol) ports.
66.243.43.21 doesn't have anything running on it.
205.188.185.33 doesn't have anything running on it. Another dead server.
192.43.244.18 Has nothing running on it. In fact, the host name actually says the following: "this.has.not.been.ntp.server.time.nist.gov.since.2012."
In light of this information, perhaps you should shoot the program developer an email and tell him that he needs to update what IPs the program uses because many of them are just simply off line and not used anymore.