The following packages have been updated in the Cygwin distribution:
* tzcode 2020a
The Time Zone Database (often called tz, tzdb, or zoneinfo) contains
data that represents the history of local time for many locations
around the world.
It is updated periodically to reflect changes made by political bodies
to daylight saving (summer time) rules, UTC offsets, and time zone
boundaries.
News for the tz database
Release 2020a - 2020-04-23 16:03:47 -0700
Briefly:
zic now supports expiration dates for leap second lists.
For more information, see the announcement or below:
https://mm.icann.org/pipermail/tz-announce/2020-April/000058.html
Changes to code
localtime.c no longer mishandles timestamps after the last
transition in a TZif file with leap seconds and with daylight
saving time transitions projected into the indefinite future.
For example, with TZ='America/Los_Angeles' with leap seconds,
zdump formerly reported a DST transition on 2038-03-14
from 01:59:32.999... to 02:59:33 instead of the correct transition
from 01:59:59.999... to 03:00:00.
zic -L now supports an Expires line in the leapseconds file, and
truncates the TZif output accordingly. This propagates leap
second expiration information into the TZif file, and avoids the
abovementioned localtime.c bug as well as similar bugs present in
many client implementations. If no Expires line is present, zic
-L instead truncates the TZif output based on the #expires comment
present in leapseconds files distributed by tzdb 2018f and later;
however, this usage is obsolescent. For now, the distributed
leapseconds file has an Expires line that is commented out, so
that the file can be fed to older versions of zic which ignore the
commented-out line. Future tzdb distributions are planned to
contain a leapseconds file with an Expires line.
The configuration macros HAVE_TZNAME and USG_COMPAT should now be
set to 1 if the system library supports the feature, and 2 if not.
As before, these macros are nonzero if tzcode should support the
feature, zero otherwise.
The configuration macro ALTZONE now has the same values with the
same meaning as HAVE_TZNAME and USG_COMPAT.
The code's defense against CRLF in leap-seconds.list is now
portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
Although the undocumented tzsetwall function is not changed in
this release, it is now deprecated in preparation for removal in
future releases. Due to POSIX requirements, tzsetwall has not
worked for some time. Any code that uses it should instead use
tzalloc(NULL) or, if portability trumps thread-safety, should
unset the TZ environment variable.