Clock unplanned offset

Hi everybody,
I have this odd problem, once in a while system time change and goes exactly 10 hours ahead, it happens to all computers clusters (not connected to each other) and to all nodes connected in a cluster.
To fix the problem I need to use the “dateâ€

1st i think date does not really affect bios-time but an offset for the OS.
2nd is there NTP or similar time-daemons running, may chaining the wrong time to the next node in cluster?

Try setting fixed Time wihtin BIOS directly or use a Master NTPd, synchronising to official NTPd and let all other nodes
just ntp on your master NTPd.

What does your time zone look like?

I don’t have NTP the cluster is isolated meaning, not connected to any large network, Micro is right of course, “date” does not effect bios time, just system time, there is the “rtc” command for this.
The problem about using one of the nodes as Master NTP is that I don’t understand the problem so it could happen also to the master.
The time zone is set somewhere between +2 to -2 (it is deferent in some clusters from others).