Update time-sync.md

Appended changed to chrony and systemd sections

Author: linuxelf001

articles/virtual-machines/linux/time-sync.md

@@ -130,11 +130,13 @@ This should return **hyperv**.
 
 ### chrony
 
-On Red Hat Enterprise Linux and CentOS 7.x, [chrony](https://chrony.tuxfamily.org/) configured to use a PTP source clock. The Network Time Protocol daemon (ntpd) doesn’t support PTP sources, so using **chronyd** is recommended. To enable PTP, update **chrony.conf**.
+On Ubuntu 19.10 or later and Red Hat Enterprise Linux and CentOS 7.x, [chrony](https://chrony.tuxfamily.org/) is configured to use a PTP source clock. Instead of chrony, older Linux releases use the Network Time Protocol daemon (ntpd) which doesn't support PTP sources. To enable PTP in those releases, chrony must be manually installed and configured (in chrony.conf) with the following
 
 ```bash
 refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0
 ```
+For more information on Ubuntu and NTP, see:
+https://help.ubuntu.com/lts/serverguide/NTP.html
 
 For more information on Red Hat and NTP, see [Configure NTP](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/system_administrators_guide/s1-configure_ntp). 
 
@@ -155,7 +157,7 @@ systemctl restart chronyd
 
 ### systemd 
 
-On Ubuntu and SUSE time sync is configured using [systemd](https://www.freedesktop.org/wiki/Software/systemd/). For more information on Ubuntu, see [Time Synchronization](https://help.ubuntu.com/lts/serverguide/NTP.html). For more information on SUSE, see Section 4.5.8 in [SUSE Linux Enterprise Server 12 SP3 Release Notes](https://www.suse.com/releasenotes/x86_64/SUSE-SLES/12-SP3/#InfraPackArch.ArchIndependent.SystemsManagement).
+On SUSE and Ubuntu releases prior to 19.10 time sync is configured using [systemd](https://www.freedesktop.org/wiki/Software/systemd/). For more information on Ubuntu, see [Time Synchronization](https://help.ubuntu.com/lts/serverguide/NTP.html). For more information on SUSE, see Section 4.5.8 in [SUSE Linux Enterprise Server 12 SP3 Release Notes](https://www.suse.com/releasenotes/x86_64/SUSE-SLES/12-SP3/#InfraPackArch.ArchIndependent.SystemsManagement).