Chrome Version       : 19.0.1084.52 (http://www.archlinux.org/packages/extra/x86_64/chromium)
OS Version           : Arch Linux ("uname -srm": Linux 3.3.7-1-ARCH x86_64)
tzdata package       : http://www.archlinux.org/packages/core/any/tzdata

Other browsers tested:
  Firefox 12.0: would work if not for double summer time bug (https://bugzilla.mozilla.org/show_bug.cgi?id=704486)
  IE 9: behaves like chromium

What steps will reproduce the problem?
Evaluate in developer console (one should setup Chromium to use Europe/Zagreb timezone):
new Date("1941-12-31T22:00:00Z")

What is the expected result?
"Thu Jan 01 1942 00:00:00 GMT+0200 (CEST)"

What happens instead?
"Wed Dec 31 1941 23:00:00 GMT+0100 (CET)"

Please provide any additional information below. Attach a screenshot if
possible.
Google group thread: http://groups.google.com/a/chromium.org/group/chromium-discuss/browse_thread/thread/4a66e94f274ccca5#


Evaluating in Linux command line:
$ LANG=hr_.HR.utf-8 TZ=Europe/Zagreb date -d '1941-12-31 22:00 UTC' +'%c %z'
# output: Thu Jan  1 00:00:00 1942 +0200

Java example:
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
df.setTimeZone(TimeZone.getTimeZone("GMT"));
df.parse("1941-12-31T22:00:00Z");
// output: Thu Jan 01 00:00:00 CEST 1942


As examples show, Chromium thinks that "1941-12-31T22:00:00Z" in
Europe/Zagreb timezone is 1941-12-31 while Linux and Java think it's
1942-01-01. The main difference, I believe, is that Chromium uses CET
while Linux and Java uses CEST (CET + summer time).


zdump output in Linux:
8<---------------------------------------------------------
$ zdump -v -c1940,1946 Europe/Zagreb
Europe/Zagreb  -9223372036854775808 = NULL
Europe/Zagreb  -9223372036854689408 = NULL
Europe/Zagreb  Fri Apr 18 21:59:59 1941 UTC = Fri Apr 18 22:59:59 1941 CET isdst=0
Europe/Zagreb  Fri Apr 18 22:00:00 1941 UTC = Sat Apr 19 00:00:00 1941 CEST isdst=1
Europe/Zagreb  Mon Nov  2 00:59:59 1942 UTC = Mon Nov  2 02:59:59 1942 CEST isdst=1
Europe/Zagreb  Mon Nov  2 01:00:00 1942 UTC = Mon Nov  2 02:00:00 1942 CET isdst=0
Europe/Zagreb  Mon Mar 29 00:59:59 1943 UTC = Mon Mar 29 01:59:59 1943 CET isdst=0
Europe/Zagreb  Mon Mar 29 01:00:00 1943 UTC = Mon Mar 29 03:00:00 1943 CEST isdst=1
Europe/Zagreb  Mon Oct  4 00:59:59 1943 UTC = Mon Oct  4 02:59:59 1943 CEST isdst=1
Europe/Zagreb  Mon Oct  4 01:00:00 1943 UTC = Mon Oct  4 02:00:00 1943 CET isdst=0
Europe/Zagreb  Mon Apr  3 00:59:59 1944 UTC = Mon Apr  3 01:59:59 1944 CET isdst=0
Europe/Zagreb  Mon Apr  3 01:00:00 1944 UTC = Mon Apr  3 03:00:00 1944 CEST isdst=1
Europe/Zagreb  Mon Oct  2 00:59:59 1944 UTC = Mon Oct  2 02:59:59 1944 CEST isdst=1
Europe/Zagreb  Mon Oct  2 01:00:00 1944 UTC = Mon Oct  2 02:00:00 1944 CET isdst=0
Europe/Zagreb  Tue May  8 00:59:59 1945 UTC = Tue May  8 01:59:59 1945 CET isdst=0
Europe/Zagreb  Tue May  8 01:00:00 1945 UTC = Tue May  8 03:00:00 1945 CEST isdst=1
Europe/Zagreb  Sun Sep 16 00:59:59 1945 UTC = Sun Sep 16 02:59:59 1945 CEST isdst=1
Europe/Zagreb  Sun Sep 16 01:00:00 1945 UTC = Sun Sep 16 02:00:00 1945 CET isdst=0
Europe/Zagreb  9223372036854689407 = NULL
Europe/Zagreb  9223372036854775807 = NULL
--------------------------------------------------------->8

Output shows that double summer time (+2h) was in place from Apr 16
1941 until 2 Nov 1942. At least according to tzdata in Linux.


UserAgentString: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/536.5 (KHTML, like Gecko) Chrome/19.0.1084.52 Safari/536.5