This can be used not only for alarms, but also scheduled maintenance routines or other such chronological tasks.
For alarms and other items scheduled for human beings, the interaction between UTC and local time can be tricky. It isn't necessarily the right thing to do to use UTC — that's almost always what you want for computers, but not for people.
For instance, if I have a wake-up alarm set for 7am, I want it to fire at 7am local time wherever I am, not at whatever UTC time was equivalent to 7am at the point at which some thing decided to tell the runtime or OS to sleep. Equally, a meeting might be set for 2pm Cupertino time or 11am London time, and I wouldn't necessarily expect that to change when DST kicked in.
I wonder if it's a good idea to suggest this is useful for alarms, therefore. It's fine for maintenance routines or timers run by a computer for a computer.