When multiple alarm clocks go off simultaneously due to snooze setting intervals. Essentially, the perfect storm of snooze.
"This morning when I woke up, it was like alarmageddon, I'm never setting them for 8:15 and 8:37 again."
Any time multiple alarm clocks go off to wake you up, usually witnessed by people who have a hard time waking up in the morning.
I had to set the alarms on my cell phone, Nintendo DS, stereo, television, and alarm clock in order to wake up. When they all went off it was alarmageddon.