On 2026-07-25 15:21, Paul Eggert via tz wrote:
@@ -28,7 +28,10 @@ Unreleased, experimental changes
hours behind UT) and "EDT" for daylight saving time, whereas it
formerly had different UT offsets before standard time was
introduced and sometimes used abbreviations like "LMT", "EWT" and
- "EPT", all contrary to POSIX.
+ "EPT", all contrary to POSIX. Also, though not required by POSIX
+ these names now use US federal rules rather than rules of places
+ like New York, reverting to 2024a behavior. This change affects
+ only timestamps before 1966-10-30 at 01:00 standard time.
After so many discussions about the "somewhat-arbitrary cutoff"
date 1970 (that lead to moving much carefully researched data into
the backzone file with "less reliable" information), and just when
we agreed to make all pre-1970 data of all time zones equally
unreliable (because a user cannot tell whether a tzdb timezone
is a Zone or a Link) -- we are now told that the pre-1970 data
of EST5EDT and its kin actually DO matter.
I do not understand - why do pre-1970 data matter for ETD5EST but
not for Europe/Copenhagen? Can't we stick to a single principle
valid for all timezones?
My second problem with the proposal is the code bloat it produces:
Why do we need a copy of the US Rules? What is wrong with
# NAME STDOFF RULES FORMAT [UNTIL]
Zone EST5EDT -5:00 US EST/EDT
Michael Deckers.
