How to Manually Enable Night Shift in iOS 11

Previously Night Shift had a dedicated button in the iOS Control Centre. But if you look in the newly redesigned Control Centre now you will see that there isn't a button for this anymore: Apple have decided it was better to hide it for some reason.

You can of course setup Night Shift active hours in your settings but if there are times when you want to manually activate it outside of those hours then you can do the following to access Night Shift in the Control Centre:

Open Control Centre

Long Press on the Brightness Control Widget

You will now see the Brightness Control Widget has expanded

Down at the bottom you will now see the Night Shift button. Just click on it to activate it

But I do recommend you have it already setup to activate at some point in the evening until daylight the next day for the small benefit it will offer your eyes.