If you've been anxious that the Apple Watch might not last long on your wrist, you can relax... well, a bit. Apple now estimates that the device will hold out for 18 hours of typical use. Just what that means isn't clear, but the company has previously suggested that this includes a lot of activity -- there was previous talk of it surviving five hours of nonstop use, which is a lot of time to spend staring at your arm. Either way, you'll definitely be charging up every night. That's on par with most other smartwatches, but it'll be a bit disappointing if you were hoping for the weeklong charges of e-paper devices like the Pebble Time.