On Sun, 29 Jan 2023 at 13:36, Thomas S. Dye <tsd@tsdye.online> wrote:
Jean Louis <bugs@gnu.support> writes:
> Time offset does not independently exists without time zone.
> While you
> represent it without time zone, you have to observe time zone
> first,
> before deriving time offset from it.
>
UTC offset exists without time zone. UTC is absolute time and
offsets from it do not refer to political time in a time zone.
They refer to local *solar time* at a particular place.
> Read from:
> https://en.wikipedia.org/wiki/UTC_offset
>
> ,----
> | Daylight saving time
> |
> | Several regions of the world use daylight saving time (DST)
> and the
> | UTC offset during this season is typically obtained by adding
> one hour
> | to local standard time. Central European Time UTC+01:00 is
> replaced by
> | Central European Summer Time UTC+02:00, and Pacific Standard
> Time
> | UTC−08:00 is replaced by Pacific Daylight Time UTC−07:00.
> `----
Your wikipedia citation puts it like this: "The UTC offset (or
time offset) is an amount of time subtracted from or added to
Coordinated Universal Time (UTC) time to specify the local solar
time (which may not be the current civil time, whether it is
standard time or daylight saving time)."
Note that the quote distinguishes UTC offset from standard time
and daylight saving time, which refer to time zones.
This distinction between absolute time (solar time) and space/time
(time zone) is fundamental. Confusing them leads to no good.
hth,
Tom
--
Thomas S. Dye
https://tsdye.online/tsdye