On 2025-05-30 12:06, PATAN JEELAN BASHA via tz wrote:
For example, in the northamerica file, we have:
Rule US 2007 max - Mar Sun>=8 2:00 1:00 D
Rule US 2007 max - Nov Sun>=1 2:00 0 S
These rules are used by zones such as America/Chicago and others.
Since Sun>=8 results in wdayoff = 0, the compat value remains 0, and the
compiler now generates TZif2 instead of TZif3.
This change affects all zones relying on similar rules, even though the rule
definitions themselves have not changed.
Specifically, the change from:
writezone(zpfirst->z_name, envvar, ZIC_VERSION); // older code
to:
writezone(zpfirst->z_name, envvar, version, defaulttype); // new code
has caused the compiler to emit TZif2 for rules that previously resulted in
TZif3.
That change in TZDB 2018f was due to this patch:
https://github.com/eggert/tz/commit/83c119f4d5d48ba37d73e42b0f12da3ae06b6c3f
which reverted this part of zic's behavior back to that of TZDB 2013c.
However, I'm not observing the behavior that you see. Regardless of
whether I build from TZDB 2013c, 2013d, 2018e, 2018f, or 2025b,
America/Chicago always uses TZif2 format.
Can you isolate the issue down to a small file that can be given as
input to zic, and for which an older zic version generates TZif3 but for
which 2025b zic generates TZif2? Also, please specify which old zic
version you're using. Thanks.
