On Wed, Dec 20, 2023 at 10:52:33PM -0600, David Wright wrote: > Sorry for the synecdoche, but I think it expresses the comprehensive > setting of UTC across the entirety of the computer and its operating > system, from the RTC, through /etc/timezone and /etc/localhost, to > the users' sessions. By this active (not just default) means, users > can remain blissfully unaware of the effects of setting timezones > other than UTC, just as the OP appeared to be, until reminded.
I'm not even sure what you're trying to say here. "Active"? Do you think /etc/timezone and /etc/localhost somehow have agency? That they have intent? They're just settings. When an application wants to convert an epoch time to a date/time string, it looks for the TZ environment variable, and if that's not present, it looks for either /etc/localtime or /etc/timezone, depending on how it was programmed. As far as the RTC (real time clock) goes, that just exists to bootstrap the system clock at boot time, before NTP takes over. If the system isn't connected to a network with a time server available, then of course NTP never takes over, and the system clock tries its best to keep up with time based on the initial RTC value, unless/until a sysadmin decides to run a date command to set the system clock more accurately. Again, there isn't any agency here. The RTC is just a resource that the system can use, once per boot, to get things started. It could be set correctly, or incorrectly. It could be set to local time, as was common when dual-booting with Windows, or to UTC. On systems that run NTP, the RTC is mostly vestigial. Its setting has very little effect on anything -- perhaps some early logfile timestamps.
