Do not disturb option

[Iskander Prime]

Not sure if I'm losing my marbles here but having bought a Z1c I stumbled upon an option to set the start and finish time the notifications would not disturb my sleep. And now I can't find it to change the times. Was it removed when kitkat was rolled out? Or do I keep missing it in settings? I know there's an App for it but don't see the point if it's on the phone somewhere.
Apologies if it's a glaringly dumb question...

 

[Messiah]

On the Z1 it is a feature of the Smart Connect App. I think you can download this from the Playstore.