Timezone not parsed correctly for Israel standard time

[Bernhard Reutner-Fischer]

On Sun, 3 Feb 2019 18:54:35 +0200
Tsvi Mostovicz <ttmost at gmail.com> wrote:

>  Hi all,
> 
> I'm unaware whether this has been fixed or if it is a real bug, but I think
> the issue is with uclibc (I thought it would be busybox, but they don't
> seem to care about timezones).
> It seems that uclibc has an issue parsing /etc/TZ file correctly for Israel
> Standard Time.
> 
> According to GNU's explanation of /etc/TZ:
> 
> "Israel Standard Time (IST) and Israel Daylight Time (IDT) are 2 hours
> ahead of the prime meridian in winter, springing forward an hour on March’s
> fourth Thursday at 26:00 (i.e., 02:00 on the first Friday on or after March
> 23), and falling back on October’s last Sunday at 02:00.
> 
> IST-2IDT,M3.4.4/26,M10.5.0"
> 
> But it seems that uclibc has trouble understanding the value of 26.
> When I set /etc/TZ as below:
> 
> echo "IST-2IDT,M3.4.4/26,M10.5.0" > /etc/TZ
> 
> and run the date command, I get the UTC time. If I change the 26 to a
> value less than 24 I get the correct time in IST/IDT.
> 
> The following report
> https://dev.archive.openwrt.org/ticket/11445.html#comment:11 seems
> related to the issue.
> 
> I have no problem creating a patch, but I couldn't find where the date
> command get's the info from the /etc/TZ file.

the TZ handling is in
libc/misc/time/time.c
tests live in test/time/
and you probably want to extend test/time/tst-posixtz.c

HTH,