Here is an example of what I mean, using the generally accepted as gospel visa calculator at
Bodrum Bulletin:So, in this completely made up example I get my visa during/for an overnight stay in Istanbul. Then, on the same visa I visit Calis for almost the entire last 3 months of the 6 months (180 days). I couldn't get it to do next day but anyway - a couple of days later I want to stay for another 3 months, and a new visa can be obtained for this.
So, if it was 90 in the preceeding 180 days, by my final leaving date of 19th September, I have stayed in Turkey for 169 days in the last 6 months. But no problem getting visas
It would only mean I couldn't get a new visa or visit again till December.
You can understand the confusion