On Sun, Mar 8, 2020 at 5:29 PM Thomas DeBellis <tommytimesharing at gmail.com>
wrote:
[snip]
A lot of that has changed nowadays with NTP clients; even if the base
operating system doesn't support time change, an
NTP client can address
that. So all my systems advanced appropriately, as did an old radio
clock. I'm not sure how *nix does it, but I don't remember Ultrix
having the code on our 8650 (or 8700). Tops-20 will do the change
whether or not a client exists as the code is in the monitor.
Unix usually maintains time internally in UTC, and conversions into a
specific timezone are handled by a userspace library and configuration
files. That's obviously not how it was done historically (time would have
been manually set by some system administrator on early systems), but it's
how it's been done since the late 80s or early 90s. The upshot however, is
that "Unix" doesn't do anything, in the sense that the kernel doesn't
care;
processes that deal with time are data driven and handle time changes
internally.
- Dan C.