On Tue, Jun 18, 2024 at 23:09:04 -0500, David Wright wrote: > On Tue 18 Jun 2024 at 07:07:36 (-0400), Greg Wooledge wrote: > > On Mon, Jun 17, 2024 at 23:54:03 -0500, David Wright wrote: > > > What should I call the timezone of my computer when it's booted up and > > > no users are logged in? > > > > Daemons will almost always use the system's default time zone (the one > > specified by /etc/localtime or /etc/timezone). > > > > It's *theoretically* possible for some daemons to be configured to use > > a different time zone, or to be hard-coded to use UTC. I've never seen > > this, but it could be done. > > In view of that, I think it's reasonable to drop the "default", > and go with "system time zone", ie the time zone that the system > clock it set to.
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. Whatever process wants to perform such a conversion will either use UTC, or the system's default time zone, or a user-specified time zone. The date(1) command has the ability to do all three: hobbit:~$ date; date -u; TZ=Europe/Moscow date Wed Jun 19 07:06:00 EDT 2024 Wed Jun 19 11:06:00 UTC 2024 Wed Jun 19 14:06:00 MSK 2024 In order, those are the system's default time zone (America/New_York in my case), UTC, and a user-specified time zone. If you want the raw epoch time, it can do that as well: hobbit:~$ date +%s 1718795213 The epoch time does not change when you use the -u option or the TZ variable, either. It's independent of those.
