I sometimes get notifications in the middle of the night from my website, twitter, and so on. I even get some of my overseas clients calling me when I should be asleep. It's not their fault, they just don't know that I am in New Zealand. I used to switch my phone to silent, but it would still buzz. I was looking through the Settings the other day and I can accross Do Not Disturb. This feature allows you to schedule the Do Not Disturb so that your iPhone or iPad does not ring or buzz after a specific time. I set this up on my phone the other day, and when a client rang me at 3:30am, I did not get woken up.