On Wed, Apr 27, 2022 at 10:45:09PM -0400, Stefan Monnier wrote:
Another option might be that your system's time was "reset".
This shouldn't happen, but it can happen if your NTP was down, the
machine got out-of-sync over time and you restart the NTP server at
which point it may(!) decide to jump the clock if the difference is
large enough (i.e. too large to catch up gradually).
Can't remember how large is "large enough".
It would depend on which NTP implementation is in use. The traditonal
"ntp" package should not do a large jump like that, except at boot. It
should just make the clock drift toward the correct time.
Other implementations may be more aggressive about it. Debian 11 uses
systemd-timesyncd by default, but I don't know how it behaves. I've
not used chrony either. I did experiment with openntpd for a while, but
it was many years ago when it was pretty new, so it might have changed
a lot.
In any case, that's a clever theory. The OP could look for evidence of
an NTP time jump in whatever logs survive from the offending time
period.