I've had my s4 for a couple of months now, but this issue just started last week. I'll notice the phone is very hot in my pocket, take it out, and see that a calendar notification has caused it to turn on, but it never turns off. And the battery is half drained. Does anyone know how to disable whatever is causing this? Very annoying, because normally the s4 has incredible battery life, but with this issue, it's as bad as my Thunderbolt! Half dead by noon!