According to the Labor Code in Turkey a Professional must work 45 hours in a week. Big companies are open from 8:30-17:00, Monday through Friday, although this might change depending on the job.
Most of the Turkish companies give two weeks vacation each year. Foreign workers should not be very hopeful that all standard western holidays (such as Christmas and Easter) to be recognized by their employers unless they work at major international companies. Time off is given for Turkish holidays, however, only If yu are not working in the tourism industry. If so, it is required that you wait for the slow winter season. Part-time employees work 7 days a week during the busy summer tourist season.
All things are taken into consideration, we may say that the Turkish Labor Code is still a work in progress. Again, that will be of your interest, If you stand up for yourself in the workplace if you feel you are being mistreated.