In SUSE, chronyd is the uses method to synchronize time. This does make sense if the server in question is the NTP-server. it also may make sense if two HA cluster nodes are configured to prefer a certain NTP server, but are configured as peers to each other. But if they only get time from one or more servers, it would be possible to implement this with systemd-timesyncd. This way, another service would be eliminated, thus simplifying the solution.
Well, at least that are my thoughts about this… are there any pro- or contra arguments to this, maybe some point I overlooked?
@Ortwin Hi and welcome to the Forum 
I suspect it depends on the installation requirements, reliability of the time souce etc, here I use a chronyd time server (RPi3/SLES 15 SP3/Battery backup for brownouts) with gps to set time for my systems on the network. IMHO it’s all about choice, use whichever time service meets your needs,
@malcolmlewis thanks!
Well, in normal installations that is most certainly true; but I wonder if in this special case (within a HA cluster) there are special requirements, so chronyd would be a better choice. (Re-reading my qeustion, I realise I did not stress the point that I was thinking indeed of the HA cluster environment, Sorry, my bad…)
So, to get my question more specific: Are there any special considerations for using chronyd within a SLE 15 HA cluster opposed to systemd-timesyncd?
@Ortwin Hi, AFAIK Cluster nodes should synchronize to an NTP server outside the cluster, so for chronyd see https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-ntp.html