This is a one time only decision, as told in http://www.timeanddate.com/news/time...dst-2011.html:
Nationwide Exam Pushes DST Start Date
The Transition to Higher Education Examination (YGS) is a nationwide exam that is scheduled to take place on Sunday, March 27, 2011. It is the first-round exam that determines the studentsí chances of being accepted into a university program.
Turkish educators objected to the DST start date because 1.5 million students will take the nationwide exam on that day. They feared that switching to DST on the same day as the exam might cause unnecessary stress for students.
Thus, the Cabinet decided to move daylight saving time to Monday, March 28 which is one day later than originally scheduled.
Basically, you have two options. First, just forget it and let your computer have wrong time for 24 hours. In my opinion, this would not be so big deal.
Second option is to disable time synchronization and summer time adjustment today, and re-enable them on Monday.