Viewing essay prompts for applications this fall

From information based on previous years, is there usually a time where the essay prompts for applying this fall for the school year of 2016-2017 are available? I will be applying to a lot of schools so I would like to start on my essays as soon as possible, preferably in late summer if they are available by then.

Late August to mid September. Don’t start too early and accidentally work on this year’s although they don’t seem to change much.