I guess it's comforting I'm not the only one. I noticed this after the last update. I use my phone as an alarm and my alarm wasn't going off. The first night I thought I just didn't charge it enough before bed. The second night, I knew it was fully charged. Midnight to 7:30am - the phone was dead. Not cool had I been on a business trip.
I thought it might have had to do with the fact that my phone has EVERY subscribed calendar on my mac. I didn't really want that and am hoping there's an option to CHOOSE which subscribed calendars sync over the air.
Anywho, if there's a fix or a new update - I'm eagerly awaiting. Otherwise, my iPhone is now a corded phone tethered to my laptop or the wall. Awesome.