On Wed, Jun 19, 2024 at 01:01:44PM -0400, Jeffrey Walton wrote: > On Wed, Jun 19, 2024 at 7:09 AM Greg Wooledge <g...@wooledge.org> wrote:
[...] > > I strongly disagree. The system clock is kept on "epoch time", which > > is the number of seconds since midnight, January 1, 1970 UTC. > > > > The system clock doesn't have a time zone of its own. It just gets > > converted to a time and date within any given time zone on demand. > > ++. > > The sharp edge is how the RTC clock is set - UTC or localtime. Also > see <https://wiki.debian.org/DateTime>. Please don't mix those three things, that makes them just more confusing. The original topic was the system's time zone. This hasn't anything to do with the RTC clock, and only peripherally with "the system's time zone" (of which some, me included, say "there's no such thing", and others disagree :) You have - the RTC clock. This is *only* looked at at boot time, to init the system clock (and when you, as an admin, do "hwclock"). During those operations, it's important to know which timezone the RTC is in, since this one /is/ in "human format. It was intended to be read and set by humans, like your kitchen clock, back then. - the system clock: it boringly counts seconds. Since Epoch. Since it has't hours or minutes, let alone weeks or months, time zones don't even make sense to it. Sometimes it does a leap second, but experts are torn on whether this was a good idea at all. Have a look at [1] for an entrance to yet another deep time rabbit hole. - timezones and stuff: those happen whenever you want to convert the system clock to hours, minutes, days, and other human related stuff and back. (if you have good net connectivity, reading the RTC at boot can be shunned completely, you don't need it anymore). Please, keep those three at a safe distance. Cheers [1] https://en.wikipedia.org/wiki/International_Atomic_Time -- tomás
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