Having a system on Armbian Focal 20.08:
$ timedatectl
Local time: Fri 2020-10-30 09:15:48 UTC
Universal time: Fri 2020-10-30 09:15:48 UTC
RTC time: Fri 2020-10-30 09:15:49
Time zone: Etc/UTC (UTC, +0000)
System clock synchronized: yes
NTP service: active
RTC in local TZ: no
There was a power outage, followed by an automatic restart of the node.
Here is an excerpt from the debug.log file:
2020-10-30T00:29:31Z [msghand] UpdateTip: new best=0000000000000000000bdfd4ceb29cedf65b4802926eac5a500ddfaa1a4d4f8e height=654711 version=0x3fffe000 log2_work=92.406717 tx=582161935 date='2020-10-30T00:19:22Z' progress=0.999997 cache=23.7MiB(169528txo)
2020-10-30T00:17:15Z [init] Bitcoin Core version v0.20.99.0-80c8a02f1 (release build)
Note that the logged time is shifted back.