[arch-general] DST-related log messages?

[Geert Hendrickx]

At least on Linux systems, the "time" isn't actually changing, as the
system clock is expressed in UTC internally (or rather, seconds elapsed
since UNIX epoch), and keeps increasing monotonically.  Only the human-
readable *display* of time is taking your local timezone into account,
and skips or repeats one hour on DST changes.

Special care must be taken when human-readable time is taken as *input*
though.  For example cron has some logic to make sure cronjobs (expressed
in local time) aren't skipped on summertime, or run twice on wintertime.
Applications may need to take care of this too.  But for the "system",
nothing changes wrt DST.


	Geert


On Sun, Nov 07, 2021 at 18:02:09 -0500, David Rosenstrauch via arch-general wrote:
> We switched from Daylight Savings back to Standard time in my locale last
> night.  (EDT -> EST)  My system did seem to update, as it has the correct
> time.  However, I was looking through the logs to see if it wrote any
> messages regarding the time changing, but didn't see any.  I also don't see
> any record of where the time got rolled back. (i.e., 03.00 -> 02.00)
> 
> Anyone know what (if anything) gets written to the logs that would show this
> change?
> 
> Thanks,
> 
> DR