The Turkish government recently announced that they will not be observing DST going forward. They will remain permanently on UTC+3 and not return to UTC+2 on October 30th, 2016.
Microsoft is preparing an update to Windows which will reflect these changes. We anticipate this update will be made available in mid October.
We recommend our customers keep their Windows devices updated to ensure the transition on October 30th, 2016 does not take effect.
In addition to the update being available in the rollups for Windows 8.1 and below (and equivalent Server versions), this DST update will also be made available as a standalone update through WSUS and Catalog. This update will be made available for Windows 10 as part of the LCU.