Question: I would like to know what the default settings for OS X are in terms of keeping the clock adjusted when I enable automatic time sync in the Date & Time preference.

I do know that the venerable `ntpd` daemon on Mavericks (10.9) and Yosemite (10.10) is no longer responsible for adjusting the time and instead a new program `pacemaker` has been introduced — so how can I know things are working or need adjustment to keep time?

Answer: 
Starting with High Sierra the ntpd system daemon was replaced with the timed system daemon which invokes /usr/libexec/timed.

The best exec I've found to get details is `systemsetup` (run as root) with its various flags:

```
[-getusingnetworktime] [-setusingnetworktime on | off]
[-getnetworktimeserver] [-setnetworktimeserver timeserver]

```

The resulting output is by far less verbose (= boring). E.g no ∂T/drift details.

Apparently *timed* uses only one ntp-server (the first one listed - checked with WireShark/LittleSnitch) even if several are entered in the system preferences/ntp.conf file.

Further reading (not very technical): [Has anyone got the time? How High Sierra has changed time synchronisation](https://eclecticlight.co/2017/10/27/has-anyone-got-the-time-how-high-sierra-has-changed-time-synchronisation/)

---

A legacy ntpd daemon is still present but unloaded. It can be loaded though by entering in Terminal.app:

```
sudo launchctl load [-F|-w] /System/Library/LaunchDaemons/org.ntp.ntpd-legacy.plist

```

in SIP disabled mode. Entering `ntpq -p` will work again then.

To load the daemon in SIP enabled mode copy the file to /Library/LaunchDaemons/:

```
sudo cp /System/Library/LaunchDaemons/org.ntp.ntpd-legacy.plist /Library/LaunchDaemons/org.ntp.ntpd.plist

```

Modify the label of the plist with nano or another editor from org.ntp.ntpd-legacy to org.ntp.ntpd:

```
sudo nano /Library/LaunchDaemons/org.ntp.ntpd.plist

```

Load the daemon:

```
sudo launchctl load -w /Library/LaunchDaemons/org.ntp.ntpd.plist

```

---

If I find a better exec to get time details with the default High Sierra daemon the answer will be updated.
To check clock sync, similar to the answer which suggests to run `ntpdate` in debug mode, you can also run it in Query mode for less verbose output.

```
$ ntpdate -q pool.ntp.org
server 85.199.214.102, stratum 1, offset 0.006256, delay 0.05470
server 95.215.175.2, stratum 3, offset 0.005234, delay 0.05624
server 217.114.59.3, stratum 2, offset 0.007166, delay 0.06274
server 85.199.214.100, stratum 1, offset 0.006319, delay 0.05396
22 Jun 09:20:55 ntpdate[84112]: adjust time server 85.199.214.100 offset 0.006319 sec
$

```

This is from my Mac running High Sierra 10.13.2, which runs `timed` rather than the NTP daemon (`ntpdate` still works because it doesn't use the NTP daemon).