School holidays
The Ministry of National Education publishes the school calendar each year, and the mid-term breaks shift. As a rough pattern: a one-week break in mid-November, two weeks at the end of January, another week in mid-April, and the summer holiday from mid-June to early September.
For a villa holiday the practical consequence is simple: the weeks that overlap a school break and a public holiday sell out first, and the shoulder weeks either side of them are where value sits.
Which weeks fill first
In Kaş and Kalkan the pattern repeats every year. Mid-July to late August is the peak, and within it the week containing 15 July and the last weekend of August go first. The Sacrifice feast is the other pressure point, especially in years when it lands close to another holiday.
If you have flexibility, the last week of May and the first two weeks of October give you the same sea with noticeably fewer people. See the month-by-month guide.