Maybe in SUS V6 POSIX.1/IEEE Std 1003.1-203X Issue 9, we could get them to drop
"name" and add "UTC offset". ;^>
Have any libraries, languages, utilities, or systems output a name for '%Z'?
On 2025-08-23 11:40, Arthur Olson via tz wrote:
Not-so-fun fact: it took about two years of lobbying to get the standard changed
from requiring a "time zone name" to requiring a "time zone name or abbreviation."
@dashdashado
On Sat, Aug 23, 2025, 1:21 PM Guy Harris via tz <[email protected]
<mailto:[email protected]>> wrote:
On Aug 23, 2025, at 9:37 AM, Paul Eggert via tz <[email protected]
<mailto:[email protected]>> wrote:
> On 2025-08-23 00:48, Peter Chamberlin wrote:
>> If there is no official abbreviation then perhaps remove the "+03"?
>
> An abbreviation of some sort is required. For more on the constraints on
abbreviations, please see <https://data.iana.org/time-zones/
theory.html#abbreviations <https://data.iana.org/time-zones/
theory.html#abbreviations>>.
In particular, "compatible with ... POSIX" refers to various mechanisms,
dating back Bell Labs UNIX, that provide a time zone abbreviation given a
time; POSIX specifies the tzname[] array.
This means that, in order to support POSIX-compliant systems, the tz
database must provide a time zone abbreviation string for all time values in
all tz database timezones.
I notice that only GNU date(1) appears to support %:/::/:::z zone formats: are
there any plans to add it to gnulib, glibc, etc. strftime(3), and document it
under the optional format prefix flags?
Could it also reuse perhaps '-' (shorter human readable formats like '%-N') as a
synonym for ':::', and/or perhaps '+' (zero pad extended precision like '%+F')
as a synonym for '::', given these all appear to be solely GNU date extensions
so far?
‘%z’
Four-digit numeric time zone, e.g., ‘-0600’ or ‘+0530’, or ‘-0000’
if no time zone is determinable. This value reflects the numeric
time zone appropriate for the current time, using the time zone
rules specified by the ‘TZ’ environment variable. A time zone is
not determinable if its numeric offset is zero and its abbreviation
begins with ‘-’. The time (and optionally, the time zone rules)
can be overridden by the ‘--date’ option.
‘%:z’
Numeric time zone with ‘:’, e.g., ‘-06:00’ or ‘+05:30’), or
‘-00:00’ if no time zone is determinable. This is a GNU extension.
‘%::z’
Numeric time zone to the nearest second with ‘:’ (e.g., ‘-06:00:00’
or ‘+05:30:00’), or ‘-00:00:00’ if no time zone is determinable.
This is a GNU extension.
‘%:::z’
Numeric time zone with ‘:’ using the minimum necessary precision
(e.g., ‘-06’, ‘+05:30’, or ‘-04:56:02’), or ‘-00’ if no time zone
is determinable. This is a GNU extension.
--
Take care. Thanks, Brian Inglis Calgary, Alberta, Canada
La perfection est atteinte Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add
mais lorsqu'il n'y a plus rien à retrancher but when there is no more to cut
-- Antoine de Saint-Exupéry
