Were you late for work or school this morning? Just tell your boss/foreman/overlord that it was all Apple's fault. That's what I did.
As first reported by Apple Insider, some iPhone users have reported a bug in the iOS 9.1 download that shuts off users' alarms while they sleep; thus royally screwing them and their future selves over. The problem isn't caused just by downloading the new software -- it's a result of a new "overnight update" feature, designed to let users endure the time-consuming software update while they sleep.
It's an ingenious idea, theoretically (because every waking moment usually finds us with our phones strapped to our palms), but this bug -- which Apple has yet to address, officially -- is making things decidedly inconvenient for people who need a phone-supported wake-up call.