[tz] [tz-announce] 2018f release of tz code and data available

Paul Eggert eggert at cs.ucla.edu
Tue Oct 23 16:26:42 UTC 2018

On 10/22/18 11:22 PM, Florian Weimer wrote:
> I mainly meant how to adjust the transition rules to get a proper POSIX
> rule.  Is this always possible?

No, because POSIX does not allow settings like 
TZ='GST3GDT,M3.5.0/-2,M10.5.0/-1', where the '-2' is short for '-02:00' 
and means that in spring the transition is at 22:00 on the day before 
the last Sunday in March. There is no POSIX-conforming equivalent to this.

We should fix POSIX to allow times outside the 00:00-24:00 range, since 
they are used in practice. Glibc supports them, and other 
POSIX-compatible implementations do too. For example, run the command 
'tail -n1 /usr/share/zoneinfo/America/Godthab' on a Red Hat platform.

More information about the tz mailing list