The timer of "Don 't Sleep" can already be set. Please first set the checkbox "Use timer". Then change the time, or set via the date and time fields (see Image 1)!
It is currently set so that the Dont Sleep blocking time by clicking the "Use Timer" check box (... see Image-1)
is automatically set to one hour.
PS: But will change it in the next version so that there is no confusion.
FAQ 7: Updated on: March 8th 2017 13:20