[JdeBP]

... unless it's the system clock in Linux, with the hardware RTC set to be interpreted as local time, and one is watching a system boot on a machine that is set up as east of the Prime Meridian (i.e. the hardware RTC is ahead of UTC). (-:

* https://unix.stackexchange.com/a/600490/5132

[dodobirdlord]

Given that Unix time specifically doesn’t handle leap seconds, a system clock is not a clock by the conventional definition.