When does Disney usually extend park hours?

[jenhelgren]

I am keeping an eye on the October hours for our trip. Are there certain days of the week/times of day that Disney does updates when they extend hours? AK hours are listed as 9pm for every Saturday in September but only 8pm for Saturdays on October--any guesses on whether October will be pushed back to 9??

 

[mesaboy2]

No set schedule to these things, sorry.