Quick post with the commands required to verify NTP configuration on a VMware Photon OS Appliance

ssh to the appliance as root

To check if the NTP service is up and running you can run this command

systemctl status systemd-timesyncd

If its stopped run this command

systemctl start systemd-timesyncd

To configure NTP servers run the following

vi /etc/systemd/timesyncd.conf

Add timeservers under [Time]