Depends on weather this year. Some year's done Oct 1, some year's Nov 1.
Then another benefit to fall lime and fertilizing. Good up sell work and keeps the lawns growing longer into the fall.
Lots of luck charging people for 30 cuts when their lawn stops growing after the 26th cut.
Last year I got 28 cuts. Because you get 28 cuts one year does not mean that you will get 28 every year.