This article discusses Time Synchronization mechanism in SPS 3.3.
In SPS 3.3, Time Synchronization mechanism was changed from previously used ntpd (in SPS version 3.0 and 3.1) to Chrony Daemon service , also known as chronyd (since SPS version 3.2). Ntpd is disabled by default. In case the ntpd service is launched, it might cause port conflict with chronyd.
To configure chronyd, refer to chrony's web site for details.