A few weeks ago, it is announced (by The Energy and Natural Resources Ministry of Turkey) that DST will be permanent and GMT+3 will be used forever in the country.
Currently, timezone of our Linux servers is set to Europe/Istanbul. But no tzdata update is released yet.
Due to lack of update, timezone will be changed from GMT+3 to GMT+2 on 30 October 2016 automatically as declared in zoneinfo file (/usr/share/zoneinfo/Europe/Istanbul).
You can see the details for 2016 below:
# zdump -v /usr/share/zoneinfo/Europe/Istanbul | grep 2016 /usr/share/zoneinfo/Europe/Istanbul Sun Mar 27 00:59:59 2016 UT = Sun Mar 27 02:59:59 2016 EET isdst=0 gmtoff=7200 /usr/share/zoneinfo/Europe/Istanbul Sun Mar 27 01:00:00 2016 UT = Sun Mar 27 04:00:00 2016 EEST isdst=1 gmtoff=10800 /usr/share/zoneinfo/Europe/Istanbul Sun Oct 30 00:59:59 2016 UT = Sun Oct 30 03:59:59 2016 EEST isdst=1 gmtoff=10800 /usr/share/zoneinfo/Europe/Istanbul Sun Oct 30 01:00:00 2016 UT = Sun Oct 30 03:00:00 2016 EET isdst=0 gmtoff=7200
(In the case of no update) To prevent this situation from becoming crisis, we decide to have a backup plan which is setting timezone of our servers to fixed GMT+3; but we face with a strange behaviour when fixed GMT+3 is set.
Let's see what are the local time and UTC time on our server before we make any change on timezone.
# date Wed Sep 21 11:13:11 EEST 2016 # date -u Wed Sep 21 08:13:15 UTC 2016
We set timezone to fixed GMT+3 as follow:
# rm -f /etc/localtime # ln -s /usr/share/zoneinfo/Etc/GMT+3 /etc/localtime
Let's see what are the local time and UTC time on our server after change. GMT+3 time is 3 hours earlier than UTC where it should be 3 hours later than UTC, as seen in the output above.
# date Wed Sep 21 05:14:24 GMT+3 2016 # date -u Wed Sep 21 08:14:26 UTC 2016
It does not change, even if we reset the local time or UTC time.
# date -s "21 Sep 2016 11:16:00" Wed Sep 21 11:16:00 GMT+3 2016 # date Wed Sep 21 11:16:02 GMT+3 2016 # date -u Wed Sep 21 14:16:05 UTC 2016 # date -u -s "21 Sep 2016 11:16:00" Wed Sep 21 11:16:00 UTC 2016 # date Wed Sep 21 08:16:01 GMT+3 2016 # date -u Wed Sep 21 11:16:02 UTC 2016
Why does the offset appear to be backwards?