If you're jonesing for an Apple Watch, you probably want to do a lot with it. But what if you're headed out to a party and would rather not risk staring at a dead screen when you're wondering how late it is? Don't worry, you're covered. The New York Times understands that the Watch has an unannounced Power Reserve option that limits the device to telling time. While it's not a completely unique feature (other watches do similar things), it's definitely helpful -- and it's a departure for Apple, whose mobile devices haven't had these kinds of extreme energy-saving modes until now. Tim Cook and crew aren't likely to make a big deal of Power Reserve at Apple's March 9th event, assuming it shows up, but it could be one of the Watch's most important real-world features.