Network Time Server command

@mnapier I can't answer why systemsetup isn't being found on your 10.11 systems, but as an alternative to editing the time server setting on your machines (which isn't possible for iOS devices) you might want to consider having your organization's DNS redirect time.apple.com to the IP address of my.network.time.server.url

@mnapier Can you use ntpdate?

I use sudo ntpdate -vu my.network.time.server.url to set the time server on my clients, so far haven't run into issues from 10.7 - 10.12.

I'm willing to share my script for this...I ran into a problem where a device off campus could not receive ntp from the authoritative server on campus for time. I was able to specify two servers with this script:

1#!/bin/bash
2
3#Primary Time server for Company Macs
4TimeServer1=<server address here>
5#Secondary Time server for Company Macs
6TimeServer2=<second server address here>
7
8# Set the primary network server with systemsetup -setnetworktimeserver
9# Using this command will clear /etc/ntp.conf of existing entries and
10# add the primary time server as the first line.
11/usr/sbin/systemsetup -setnetworktimeserver $TimeServer1
12
13# Add the secondary time server as the second line in /etc/ntp.conf
14echo "server $TimeServer2" >> /etc/ntp.conf
15
16exit 0

Now I know that this wasn't your primary problem, but note the syntax of setting the timer server for the second server. This method would work to set the time server for the primary as well. Not the other way around though...in my case systemsetup works but systemsetup command only can specify one server so I use the second command to specify the second one. Hope this helps someone.

Question: how does the system know when to use the second time server?

Honestly unsure...I'm guessing it tries to hit the primary and when it can't looks for a secondary. That is the design assumption I am making when I use it. If someone is in house, we want them to hit the domain controller for their time. Our domain controller is not available off the network though and people's clocks sometimes go weird so I make the second server time.apple.com